The Hyogo-ken Nambu earthquake occurred January 17, 1995 at 5:47 a.m. local time near the city of Kobe, Japan. The Northridge earthquake occurred on exactly the same calendar day one year earlier. The Mw 6.8 earthquake caused over 5,000 deaths and extensive property damage in a highly urbanized area of Japan.
Several NCEER investigators were in nearby Osaka, Japan when the earthquake occurred, to attend the Fourth U.S.-Japan Workshop on Urban Hazards Reduction, organized by the Earthquake Engineering Research Institute (EERI). They participated in reconnaissance efforts following the earthquake, and their insights and impressions are included in NCEER Response, a supplement to this issue of the NCEER Bulletin. Several other NCEER researchers have visited the Kobe area since the earthquake, and have also contributed to NCEER Response.
NCEER's reconnaissance efforts will focus on lifelines. Five Center-sponsored researchers are scheduled to arrive in Kobe February 12 to investigate the performance of highways, water systems, gas systems, telecommunications and electric systems. The researchers are part of a team of 18 engineers and scientists assembled by the National Institute of Standards and Technology (NIST) and are traveling under the auspices of the U.S.-Japan Natural Resources (UJNR). The team will be hosted by the Public Works Research Institute of Japan.
A detailed reconnaissance report is expected to be published by NCEER this spring.
This article presents research conducted to date on the de-velopment of models for analyzing the economic role of utility lifelines damaged and/or disrupted by earthquakes. Comments and questions should be directed to Professor Adam Rose, The Pennsylvania State University, (814) 865-2549.
Some services are so crucial to our society that they are commonly referred to as lifelines. Foremost among these are utilities such as electricity, gas, and water. In addition to their contributions to health and safety, they are the lifeblood of the economy. Unfortunately, the network character of lifelines makes them especially vulnerable to disruptions from earthquakes and other natural disasters.
For the past two years, NCEER has supported the development of a modeling framework for analyzing the magnitude of economic losses, the role of mitigation, the optimal recovery pattern, and the optimal reconstruction strategy with respect to utility lifeline disruptions caused by earthquakes. A modeling approach has been chosen that is able to trace the workings of utility lifelines within a regional economy. It has been extended to an optimization framework to identify policies to minimize losses and maximize recovery. Further extensions incorporate stochastic elements to take into account the costs of uncertainty and the value of information in these processes.
Since its inception, NCEER lifeline research has covered important considerations such as seismic vulnerability, retrofitting, and damage assessment. As such, this research has been the province of geologists and engineers. In recent years, the research effort has expanded to include social scientists, who are focusing on the development of mechanisms to translate physical lifeline damages into economic terms.
Most prior assessments of earthquake losses have been based on damaged property, which economists refer to as capital stock. But it is the flow of goods and services from this capital stock that is the better measure of economic well-being (e.g., Gross National Product is an example of such a flow measure). One way in which this is an obvious distinction, especially pertinent to lifelines, is when a factory is unscathed by an earthquake, but is unable to operate because one or more of its utility lifelines services is disrupted.
Attention to this consideration by NCEER and other researchers represents an important first step in this process (see for example Applied Technology Council, 1991 and Eguchi and Pelmulder, 1991). These studies have measured losses to direct customers in terms of foregone production. Still, losses do not end with what economists refer to as partial equilibrium (single market) assessments. We live in a highly interdependent economic system, where one sector is dependent on several others for inputs and is the supplier of inputs to still other sectors. Thus, the shutdown of a steel mill due to a power outage may also affect the operation of an automobile manufacturer, thereby causing a second-round of business shutdowns. The production decreases by the automaker then reduces the flow of cars to auto dealers, as well as causing a reduction in the derived demand for tires and other inputs. Several other upstream and downstream ripples ensue. The sum total of them is some multiple of the direct losses, and hence are referred to as multiplier effects.
Losses of course do not end with these interindustry interactions, but also include industry-household interactions. That is, factory shutdowns result in lost wages and dividend payments, which then translate into lower consumer spending. This sets off a further chain reaction that broadens the multiplier effects. Overall, losses stemming from utility lifeline disruptions are felt throughout the economy and are therefore best addressed by a general equilibrium (multi-market) framework.
A set of economic models especially well-suited to such issues are referred to as interindustry, multisector, or applied general equilibrium. At the core of each one is an economic data tabulation called an input-output table.
The basic Input-Output (I-O) model can be defined as an operational, static, linear model of purchases and sales between sectors of the economy, based on the technical relations of production (Miller and Blair, 1985). Many of the limitations of the basic model have been overcome by progress toward a more general model, which is defined as a dynamic, non-linear model of purchases and sales of commodities between sectors and institutions of an economy or economies based on the technical relationship of production and other important quantifiable variables. In this light, the current state-of-the-art of I-O economics represents a formidable modeling option with a wide range of applications (Rose and Miernyk, 1989).
Linear Programming (LP) refers to the class of problems in which one seeks to optimize a linear objective function subject to linear constraints. A good way to understand the relationship between LP and I-O is through the field of activity analysis in which linear combinations of input are used to produce an output or set of outputs. In essence, I-O is a simple case of activity analysis where each good is produced by a single technology and there are no joint outputs. LP is a solution algorithm to an activity analysis problem (as well as other types of problems).
I-O and LP can be combined in various ways. One characterization of this combination is a reference to models that include choice on the demand side and those that include choice on the supply side. The demand side formulation calls for varying the mix of final demands to maximize some objective function. In our context, for example, this might entail minimizing the loss in Gross Regional Product by rearranging production to achieve the highest level of output following an earthquake event. Choice on the supply side can take many forms, including determining the best technology to produce a certain output. In our context, this might mean choosing the optimal method of electricity generating technology.
The authors have developed a hierarchy of interindustry models, which are demarcated according to their ability to include complexities of lifeline issues (Rose and Benavides, 1993). As one moves up the hierarchy, the model is able to incorporate more of such considerations as import substitution, conservation, external aid, technological change, investment, and uncertainty. The models at the lower end of the hierarchy can be utilized by those with somewhat limited backgrounds in economics and computer modeling and are intended to provide ballpark estimates of economic losses due to lifeline disruptions. The upper-tier models require advanced knowledge of economics, utility lifelines, and computer programming, and are intended to provide more accurate impact assessments and policy analyses.
The U.S. Forest Service Impact Analysis for Planning System (IMPLAN) (U.S. Forest Service, 1993) is being used to construct our regional I-O tables. IMPLAN consists of a large database and algorithms to compile regional I-O tables and to perform various types of impact analyses. The system can generate I-O tables for any county or county grouping in the U.S., even for regions that transcend state boundaries.
IMPLAN generates tables at a level of dissagregation that includes more than 500 sectors, in order to minimize the cross-hauling (simultaneous import and export of the same commodity) problem. Such large matrices are somewhat unwieldy and can readily be aggregated to any level appropriate to the case in point.
IMPLAN produces the following outputs:
MARKAL (MARKet ALlocation) (Brookhaven National Laboratory, 1994) is also being used, which is a linear programming approach to energy system optimization based on the concept of process (activity) analysis and originally implemented at Brookhaven National Laboratory and Juelich Kernforschungsanlage (Germany) under the sponsorship of the International Energy Agency (IEA). In MARKAL, the energy flows are represented through a set of production, transformation, and end-use technologies in a country, region, or economic sector. The model is dynamic, as it provides a representation of the evolution of the installed capacity, and can be used at different levels of aggregation.
A MARKAL model produces the following output:
o A capacity expansion schedule for a given set of energy technologies
o An operation program for technologies with a positive capacity
o An accounting of all energy forms used in each sector of the economy
o A shadow (efficiency) price for each energy type
An input-output transactions table for Shelby County, Tennessee (basically the core of the Memphis Metropolitan area) is presented in table 1. The table was derived from the IMPLAN system. To facilitate the presentation, the 500 sectors of the region's economy have been aggregated to 15 sectors.
This I-O table is an intraregional requirements version, i.e., the entries in rows and columns 1-15 represent only those goods produced in the region that are also consumed there. This excludes exports (which are part of final demand) and imports (presented in a lower row of the table). The exception is electricity, which is generated entirely outside the region. For the purpose of illustrating the key role of electricity, it has been included within the transactions table (intraregional commodity flows), but it is not actually part of the Total Regional Intermediate Input subtotal. Also, the fact that electricity is not generated within the County borders is the reason all of the entries in column 11 are zero.
An I-O table contains a set of double-entry accounts. Each row represents the sales of the sector listed at the left to all other sectors, whose identities are given by the corresponding sector numbers along the top margin (column headings). Each column represents the purchases by a given sector from all other sectors in the region, as well as purchases of imports and primary factors (capital and labor are listed in the value-added row) and final demand (comprised of consumption, investment demand, government expenditures, and exports). For example, the table indicates that in 1991 the Electric Utilities sector (11) sold $1.6 million and $29.4 million to intermediate sectors such as Agriculture (Sector l) and Machinery and Miscellaneous Manufacturing (Sector 9), respectively, as well as $78.7 million to Personal Consumption (residential customers). Total gross output (sales) of electricity in Shelby County in 1991 was $216.9 million.
The I-O table also provides insight into the general structure of the Memphis economy. It indicates Memphis is both a major commercial center and a major manufacturing centerthe Services and Miscellaneous aggregate is the largest producer, with a gross output of $14.9 billion. Overall, the County is highly self- sufficient, with imports of $7.8 billion out of a total gross output of $34.3 billion. Gross Regional Product is given by the total value-added of $19.5 billion. This is equal to total final demand of $27.4 billion minus imports of $7.8 billion.
Depending on the extent of physical damage to generating plants, substations, and transmissions lines, it may be possible to reallocate electricity services among customers following an earthquake in order to meet priority needs for health and safety and to minimize losses to the regional economy.
As the duration of the disruption increases, selective rationing of electricity services becomes an attractive option. It is sometimes overlooked by engineers because of the technological features of electricity lifelines, i.e., unlike water, where the flow can be reduced, electric power is either on or off. Also, power system shutoff to individual customers is not always feasible, but there are other mechanisms. A good example stems from the recent response to the extreme winter in the eastern United States. In late January, 1994, in Pennsylvania, utilities instituted rolling blackouts. In addition, the Governor issued a decree (at the request of the utilities) closing State government offices and requiring non-essential industry to close down.
An alternative to this approach is interruptible load clauses, i.e., contracts calling for firms to be subject to curtailments in exchange for discounted electricity prices. In this case, rationing is based on market incentives. However, one problem that arises is that customers will make choices according to their own private costs and fail to consider broader general equilibrium implications. For example, a business enterprise may pay the premium for non-interruptibility, but may still be forced to shut down if any of its major direct or indirect suppliers within the region fail to do so.
Using a combination of I-O and LP models in a stylized simulation of a catastrophic earthquake in the Wasatch Fault Earthquake Zone (basically metropolitan Salt Lake City, Utah), the authors compared the effect of three policies: 1) proportional cutback to all customers, 2) centralized rationing to minimize losses in Gross Regional Product, and 3) interruptible load contracts for those sectors that typically rely on them.
The results indicated that the second of these two options is the far superior alternative. It should be noted, however, that a crude version of our hierarchy of models was used and all of the relevant considerations thus far have not yet been examined.
At the upper level of our hierarchy of models, an adapt-ive decision-making tool for investment in electricity generation and transmission facilities during the re-construction period has been developed. Stochastic pro-gramming with recourse was used to model a decision-making process in which choices are adapted as reali-zations of random variables become known. Demand was modeled as a random variable whose values follow a binary tree over time. Using binary variables for investment and continuous variables for operation levels, the model can be solved by mixed-integer programming. Construction lags have also been incorporated.
The model has been implemented in a case study for Utah's power system to compute a contingent expansion strategy that should be followed after a hypothetical earthquake in the Wasatch Fault Earthquake Zone. It was assumed that a catastrophic earthquake at the beginning of 1995 would result in 20% (591 MW) of coal-fired electric power plant capacity being irreversibly damaged. An uncertain rate of growth in electricity demand during the six years following the earthquake was assumed, reflecting different extents and speeds of rebuilding efforts and changes in economic opportunities.
Results of the simulation indicate that the optimal reconstruction strategy would consist of a natural gas plant of 150 MW during the first period (each period taken as two years) in both possible scenarios, followed by the commissioning of two coal plants (500 MW in total) and a combined cycle plant of 150 MW for three of the four second period possible evolutions of demand. A transmission line for imports up to 100 MW would be required in only the two scenarios with highest growth during the third period.
An important aspect of the simulations was the calculation of Expected Value of Perfect Information (EVPI), the difference between the cost of the optimal recourse problem and the expectation of solution values that would be obtained if the future were known perfectly. The cost of the optimal strategy was $5.1 billion, and the EVPI computed was only $26.7 million, reflecting the lack of flexibility imposed by time-to-build constraints and the relatively mild uncertainty that was modeled. Also, the solution replicated the well-known principle of order-of-merit dispatch.
During the past year, the work described in this article has begun to be integrated with that of other NCEER researchers in terms of case studies of a potential New Madrid earthquake and the actual Northridge earthquake of January, 1994. This includes work on lifeline damages by Dr. M. Shinozuka (Princeton University), Dr. A. Schiff (Precision Measurement Instruments), Dr. H. Hwang (University of Memphis), and Dr. C. Scawthorn and Mr. R. Eguchi (EQE International); work on GIS mapping by Dr. S. French (Georgia Institute of Technology) and on subregional social accounting by Dr. S. Cole (University at Buffalo) that can help us link lifeline damages to a sectoral classification of customers; and survey work by Dr. K. Tierney (University of Delaware) that will help us more pre-cisely ascertain losses in production. We are fortunate to build on these valuable prior and ongoing research efforts. We hope that our analyses will help extend the frontiers of hazards research even further, while also providing valuable information for policymakers.
Applied Technology Council, (1991), "Seismic Vulnerability and Impact of Disruption of Lifelines in the Coterminous United States," Distributed by the Federal Emergency Management Agency, Washington, DC, USGPO.
Brookhaven National Laboratory, (1994), The MARKAL/ MARKAL-MACRO/MUSS Modeling System: Extensions and Use, Upton, New York.
Eguchi, R. and Pelmulder, S., (1991), "Indirect Economic Impacts of Energy Network," in Indirect Economic Consequences of a Catastrophic Earthquake, Federal Emergency Management Agency, Washington, DC.
Miller, R. E. and Blair, P.D., (1985), "Input-Output Analysis: Foundations and Extensions, Englewood Cliffs," NJ, Prentice-Hall.
Rose, A. and Mierny, W., (1989), "Input-Output Analysis: The First Fifty Years," Economic Systems Research 1, 229-71.
Rose, A. and Benavides, J., (1993), "Interindustry Models for Analyzing the Economic Impacts of Earthquakes and Recovery Policies," Report to NCEER, Department of Mineral Economics, The Pennsylvania State University, University Park, PA l6802.
U.S. Forest Service, (1993), Micro IMPLAN: A User's Guide, Rocky Mountain Experiment Station, Ft. Collins, Colorado.
This article presents work conducted on the effect of liquefaction on lateral pile response during the first year of NCEER's Highway Project. Research was conducted at Rensselaer Polytechnic Institute using the geotechnical centrifuge facility. For more information, contact Professor Ricardo Dobry, Rensselaer Polytechnic Institute, (518) 276-6934.
Many existing bridges are founded on piles driven through loose sand that may liquefy during earthquake shaking. Both lateral stiffness and lateral capacity of piles are very sensitive to the properties of the surrounding soil, be them friction or end-bearing piles. In current seismic analysis procedures, the effect of soil on lateral response is incorporated through nonlinear distributed soil springs along the pile within a beam-on-elastic foundation formulation. The pressure-deflection curves character-izing those springs, called p-y curves, depend on pile diameter, soil properties, and state of effective stresses (Cox, Reese and Grubbs, 1974; and Reese, Cox and Koop, 1974). Therefore, it is of great interest to evaluate the influence of the pore water pressure buildup in the sand due to the shaking on the p-y curves controlling the lateral response of the pile during the rest of the shaking. This is being done in this project by means of centrifuge model testing at the Rensselaer Polytechnic Institute 100 g-ton geotechnical centrifuge in Troy, New York. It is expected that this will result in a proposed guideline for seismic analysis of piles in liquefying sand.
The basic centrifuge model is shown in figure 1. An end-bearing model pile, with its tip fixed to the bottom of the box, is surrounded by saturated sand having a relative density, Dr ( 60%. Seismic shaking of limited duration is applied in-flight to the base of the rigid container to induce an excess pore pressure in the sand. At this stage, no relative displacement pile-soil is desired; the pile head is therefore kept locked and the pile moves together with the container during the shaking.
Immediately after shaking, and while there are still excess pore pressures in the soil, the pile head is unlocked, and a cyclic (but static) lateral load test is conducted in-flight through a horizontal actuator located above the ground surface. During this load test, rotation of the pile is prevented, thus enforcing a fixed-head condition. The force-displacement relation at the pile head is measured with a load cell and with an LVDT, respectively; the bending strains along the pile are determined by means of strain gages (SG), and the excess pore pressures in the sand are monitored through miniature piezometers (P), as shown in figure 1. To avoid too rapid a dissipation of excess pore pressures after the end of shaking due to the increased permeability of the soil in the high g-field, a deaired water-glycerol mixture is used as pore fluid, which has a viscosity about 10 times greater than water.
The purpose of this centrifuge model is to establish the effect of excess pore pressure in the sand on the p-y curves at different depths along the pile. Most of the tests in the project use the basic model just described, and do not involve structural inertia forces. A test involving a mass on top of the pile during base shaking, so as to develop truly seismic loading rather than cyclic loading through an actuator, is planned for a later date for verification purposes.
A prototype steel pipe pile 22 ft. long, 15 in. outside diameter, and with a bending stiffness EI = 9.95 x 106 kip-in2 was selected as reasonably representative of many highway bridge foundations. After taking into account the scaling factor of 40 for all linear dimensions for a 40-g centrifugal field, a model brass pile with the properties listed in table 1 was selected.
Table 1: Model Pile Properties
Length (in) O.D. (in) I.D. (in) Material Modulus of elasticity (psi)
6.625 0.375 0.347 Brass 15x10 E6
The soil deposit has a dimension of 20 in. (L) x 10 in. (W) x 6.625 in. (H), simulating a prototype scale saturated sand deposit of about 22 feet thick resting on stiff bedrock. The model pile is installed in the model container with its tip fixed at the bottom. Dry Nevada No. 120 sand is then drained into the container with relative densities in the range of 62 ( 3%. Pore pressure transducers are installed at various depths during this process. Compaction around the pile is applied by layers to minimize the difference between the actual driving process and the installation process used in the test.
The soil model is then vacuumed and saturated with the deaired water-glycerol mixture. The resulting permeability of the prototype soil deposit being modeled is 10-2 cm/s. After saturation, the loading unit is installed on the model, the computer-operated actuator locks the pile head electronically in a neutral position and a zero slope boundary condition at the pile head during the test is secured. The pile-soil model is then spun up to 40 g in the centrifuge for consolidation. Base shaking is applied at the model base in flight after the soil stratum is fully consolidated and all instruments have reached steady state. The shaking and lateral loading are synchronized in such a way that immediately after base shaking ends, the computer unlocks the actuator and the lateral loading at the pile head starts. In practice, this means that the lateral loading starts 100 milliseconds (4 seconds in prototype time) after the start of base shaking. Data from 16 channels are acquired at 50 kHz and saved directly on the computer hard drive.
The main centrifuge model testing program is shown in table 2. These tests have all been completed. Test PL16 was conducted without soil, and Test PS01 with soil but no shaking. The rest of the tests included both shaking followed by a cyclic lateral load test at the pile head, as already described. The average base acceleration applied to the system during the shaking stage, as listed in the table, is in prototype units; that is, actual horizontal accelerations 40 times larger were applied in-flight to the base of the model. The values of ru listed give the range of maximum excess pore pressure ratios measured by the piezometers at various depths.
Table 2: Model Testing Program
Tests Soil Average Base Shaking Range of Maximum ru Acceleration (g) Over Deposit Thickness
PL16 No --- ---
PS01 Saturated No ---
PS02 Saturated 0.400 100%
PS03 Saturated 0.145 61% - 100%
PS06 Saturated 0.060 32% - 100%
PS07 Saturated 0.340 95% - 100%
The model pile was first calibrated in Test PL16 while spinning the centrifuge at 40 g without placement of any soil in the model container. No shaking was done in this test. Lateral loading was applied at the pile head while in-flight. The pile stiffness, boundary conditions, pile head displacement, and force and bending moments were verified with the theoretical solutions for a pile without soil fixed at both ends, with good agreement.
The pile-saturated soil model was then calibrated in Test PS01 by lateral loading in flight without any base shaking. A set of p-y curves was obtained from the measurements, following the same method typically used to develop conventional p-y curves from full scale pile loading tests in the field. These p-y curves obtained from Test PS01 are summarized in figure 2. Figure 3 compares the measured bending moments along the pile (data points) with those predicted using these p-y curves (lines) for several values of the pile head displacement. The figure also includes comparisons of predicted and measured pile head force F0.
Next, Tests PS02 to PS07, all of which involving shaking followed by lateral loading, were conducted to observe the p-y response at various levels of pore pressure ratio in the sand. The only difference between these various tests was the amplitude of base shaking acceleration, which in turn developed different levels of pore pressure ratio (table 2). Selected short term and long term records measured in Test PS07 are plotted in figures 4 and 5 in prototype units.(1) Figure 4 includes the following measured time histories: (a) base horizontal acceleration, (b) pore pressure ratio at a depth of 8.7 feet, (d) pile head lateral displacement, (f) pile head force, and (c) and (e) two of the pile bending moments measured by the corresponding strain gages. The average amplitude of the input base acceleration in this test was 0.34 g, strong enough to liquefy the soil stratum almost completely. It can be seen that the pore pressure ratio ru reached 100% very rapidly, as shown in figure 4(b). The pile head was locked during the shaking (no displacement); still, a cyclic lateral force and cyclic bending moments along the pile were measured during shaking due to inertial forces developed in the loading unit and the soil. Figure 5 shows the long term time histories of: (a) pile head lateral displacement y0,
(1) To get these prototype units, the actual model measurements have been multiplied by a scaling factor as follows: a factor of 40 for time and displacement y0, a factor of (40)2 = 1,600 for force F0, a factor of 1/40 for acceleration a, and of (40)3 for moment M; the pore pressure ratio ru has a scaling factor of unity.
(b) force F0, and (c) pore pressure ratios ru at various depths, during and after shaking. The small gap in the records at about 53 seconds was caused by an unexpected interruption of the data acquisition system, when the acquisition rate was switched from fast to slow. Fortunately, the gap is small and the missing data can be easily interpolated. As observed previously, at any given time the pore pressure ratio was not constant with depth; instead, it was usually greater at shallow elevations.
Figure 5 shows some of the key data provided by the lateral load test conducted after the end of the shaking (t > 5 seconds). A slowly varying lateral cyclic displacement of ( 2 inches was applied to the head of the pile. The frequency of the loading was low enough so that it induced no significant inertia forces. The corresponding force-displacement relation could be correlated with the pore pressure ratio simultaneously measured in the soil (figure 5(c)). As the pore pressures dissipated with time, the soil stiffened and the force needed to reach the 2 inch displacement increased (figure 5(b)), thus providing in one test measurements ranging all the way from ru = 100% to ru = 0.
Measurements of pore pressures such as those illustrated in figure 5(c) showed cyclic fluctuations during the application of cyclic load at the pile head, especially for shallow depths and when ru was low. This suggests that dilation occurred due to the pile deflection, as the pore pressure transducers were installed only about 3.5 ft. from the pile. The pore pressures measured by the piezometers were used directly in the analysis, with no attempt to separate the pore pressure into components caused by prior shaking and by pile deflection.
The lateral force F0 measured at the pile head when y0 = ( 2 inches, is plotted in figure 6 versus the pore pressure ratios measured in the soil at the same time. Figure 6 includes data from Tests PS02 to PS07, and from all relevant loading cycles. Each value of force is related to a range of pore pressure ratios at various depths, as defined by the corresponding bar in figure 6. In most cases, the right end of the bar is associated with pore pressure ratios at shallow depths, while the left end corresponds to deep elevations. The lateral force at a 2 inch displacement in Test PL16, without soil, and that in Test PS01, with soil but without shaking, have been plotted as data points in figure 6. These two data points bound all possible values of the pile head force: maximum possible force (soil and zero pore pressure ratio), and minimum possible force (no soil). The measurement bars in figure 6 fall between these two bounds, with the value of lateral forces decreasing as the pore pressure ratio increases, more or less following a linear pattern.
A more precise, but still preliminary, analysis of the data contained in figure 6 was conducted, using program LPILE and an assumed law relating pore pressure ratio and degradation of the p-y curves for ru = 0 determined in figure 2. In this way, the large scatter of the measurement bars of ru in figure 6 was significantly reduced, as shown in figure 7. In this plot, dimensionless degradation parameter Cu is more or less uniquely correlated with ru.
Figure 8 shows the results of using the new, degraded p-y curves, including Cu obtained from figure 7, in the prediction of results measured in Test PS07. The measured pore pressure ratio distributions with depth are shown at the right hand side, while the predicted pile head lateral force and bending moments are included in the left-hand side of figure 8. The predicted bending moment lines compare very well with the data points measured with the strain gages. Comparisons such as figure 8 and other analyses will be used to support the proposed guidelines for the development of degraded p-y curves in a soil totally or partially liquefied by earthquake shaking.
Cox, William R., Reese, Lymon C., and Grubbs, Berry R., (1974), "Field Testing of Laterally Loaded Piles in Sand," Sixth Annual Offshore Technology Conference, Houston, Texas.
Reese, Lymon C., Cox, William R., and Koop, Francis D., (1974), "Analysis of Laterally Loaded Piles in Sand," Sixth Annual Offshore Technology Conference, Houston, Texas.
NCEER has established a users group for interactive support of the Three-Dimensional Nonlinear Analysis of Building Structures (3D-BASIS) computer program. The users group will obtain support from the developers at the University at Buffalo and the University of Missouri/Columbia in the start-up and routine operation of the program. Users group members will obtain updates to the program. Based on feedback from users, the program developers will provide further improvements and enhancements which will be included in subsequent versions. The developers will provide limited assistance in the use of the program.
Members of the users group will receive the current version of the program along with a users manual and examples, as part of their membership. The users will be able to obtain updated versions of the program at a discounted fee.
A one-time enrollment fee will be charged for membership as follows: university and research institutional user fees are $275, commercial user fees are $550, and foreign users will be charged an extra $25 for shipping the materials.
The establishment of the users group coincides with the release of a new version of the program, 3D-BASIS-TABS, Version 2.0. This version includes corrections to the previous programs based on feedback from users. Moreover, this version includes the following new features:
Three options for modeling the linear superstructure: Option 1 - three-dimensional shear building representation, in which case the global stiffness matrix of the superstructure is assembled internally by the program using story stiffnesses, specified by the user, followed by the dynamic analysis (as in the previous version); Option 2 - full three-dimensional representation, in which case beam, column, shear wall panels and bracing elements of the superstructure are modeled explicitly, followed by assembly of the global stiffness matrix, condensation, dynamic analysis, and recovery of internal forces in structural elements by backsubstitution (new); and Option 3 - three-dimensional representation, in which case the dynamic characteristics of the superstructure, such as frequencies and mode shapes, specified by the user, are used to compute the superstructure stiffness matrix, followed by dynamic analysis (as in the previous versions).
Option 2 in 3D-BASIS-TABS now offers the capability to compute superstructure member forces, after the completion of the nonlinear time history analysis, followed by output of peak member forces, which can be used for the design of members.
Additional models for isolation elements, such as FPS, HDR, etc., were added for convenience of analyzing a mixture of supports where necessary.
Additional models for nonlinear and hysteretic dampers were added for analysis of complex fluid, nonlinear viscous, friction and hysteretic dampers complementary to the bearing system.
Additional effects of motion on modeling of bearings, i.e., effects of vertical accelerations and varying normal forces
Additional example problems in an improved manual with special features for input and output.
Version 2.0 was developed for use on any of the following operating systems: PC/DOS, UNIX or VMS; note that there are special features in the PC/DOS version. This unified version was extensively tested with experimental data and other computer models. Technical information is described in NCEER Technical Report NCEER-94-0018, 3D-BASIS-TABS Version 2.0, Computer Program for Nonlinear Dynamic Analysis of Three Dimensional Base Isolated Structures (available from NCEER Publications for $15.00) and in the subsequent users manual.
New members of the users group will receive Version 2.0 as part of their membership. For additional details, contact Professor Andrei M. Reinhorn at the University at Buffalo, phone (716) 645-2114, ext. 2419, email: email@example.com or Satish Nagarajaiah at the University of Missouri/Columbia, phone: (314) 882-0071; email: firstname.lastname@example.org.
The developers are currently working on a project to retrofit structures using supplemental damping. A future release, Version 3.0, will include modeling supplemental damping devices, i.e., fluid, viscoelastic, hysteretic and friction devices. This version is currently being verified using the results of recently completed shaking table experiments of a reinforced concrete structure equipped with various damping devices. In addition, a new program for the analysis of inelastic superstructures is being developed and is in the testing stages.
The U.S. Geological Survey (USGS), in cooperation with NCEER and the Building Seismic Safety Council (BSSC), convened a workshop on Seismic Hazard Mapping in the Northeastern United States on August 2-3, 1994 at Lamont-Doherty Earth Observatory (LDEO). The workshop is one of a series to discuss input parameters and methodology for the new national seismic hazard maps to be produced by the USGS. These new maps will be included in the 1997 edition of the NEHRP Recommended Provisions for the Development of Seismic Regulations for New Buildings (published by BSSC) and will be the starting point for design value maps in that document. The workshop was attended by 26 geoscientists and engineers.
The first speaker was Arthur Frankel (USGS), who proposed a three-model framework for the hazard maps for the central and eastern United States. This approach, after some modification, was adopted as the consensus methodology by most of the workshop participants. The hazard models are discussed in detail in the next section. Two of the models are based on spatially-smoothed representations of historical seismicity and one model is a broad background zone. Frankel presented several preliminary maps of probabilistic ground motions based on this approach.
Klaus Jacob (L-DEO; NCEER) presented probabilistic hazard maps for New York State based directly on spatially-smoothed activity values (a-values) derived from seismicity recorded on the regional seismic network (Jacob et al., 1994). He compared these maps to the USGS hazard maps of Algermissen et al. (1990) and discussed their similarities and differences. John Ebel (Boston College) described the seismic hazard map produced for Vermont and vicinity. Martin Chapman (Virginia Polytechnic Institute) showed probabilistic hazard maps produced for Virginia Polytechnic Institute (see Chapman and Krimgold, 1994).
There was a lively discussion about the relative importance of historical seismicity and potentially-seismogenic geologic structures in hazard maps for the northeast. Most workshop attendees felt that generalizations of historical seismicity were more useful than geologic source zones for ground motions with annual probabilities of exceedance of 0.001 or larger (10% probability of exceedance in 100 years or less). Paul Pomeroy and Noel Barstow (L-DEO) described eastern U.S. seismicity in general. Barstow noted that magnitude 5 earthquakes in the eastern U.S. have generally occurred in areas of relatively high seismicity for small earthquakes (about magnitude 3). John Ebel described geologic structures in Massachusetts which may be associated with seismicity. Russ Wheeler (USGS) discussed a scheme of broad geologic source zones based on the age of rifting episodes: 1) faults activated during the formation of the proto-Atlantic (Iapetus) Ocean 650-550 million years ago and 2) faults activated during the opening of the Atlantic Ocean 100-200 million years ago.
Workshop participants spent much time discussing earthquake catalogs and magnitude scales. For the eastern and central U.S. it is particularly critical to assign accurate magnitudes for historic earthquakes that occurred before the advent of seismometers. The participants agreed that the best catalogs use felt area to determine the magnitude of historic events, rather than maximum intensity. Matthew Sibol (Virginia Polytechnic Institute) showed his results for converting from felt area to body wave magnitude mb, for central and eastern U.S. earthquakes. Paul Somerville (Woodward-Clyde) described a discrepancy between observed mb-moment magnitude relations for the 1925 Charlevoix earthquake and those derived from other events. The USGS plans to use the Seeber and Armbruster (1991) catalog in the hazard mapping process, which uses felt area to determine the magnitude of historic events when possible.
The morning of the second day was largely devoted to consideration of attenuation relations. The participants agreed that using one set of relations based on a stress drop of 200 bars was the most reasonable approach. They generally felt that attenuation relations based solely on the Saguenay earthquake were not appropriate for median values of ground motion because of the high stress drop of that event. The ground motions for the Saguenay event could be accounted for in the variability of ground motion attenuation relations. William Joyner (USGS) described the spectra found for the Saguenay event and a two-corner frequency model that could explain them.
There was some discussion of the reference site condition for the national hazard maps. Jacob described the recently-adopted set of amplification factors for different site classes based on their shear-wave velocity in the upper 30m. These site classes and amplification factors were approved for the 1994 edition of the NEHRP Provisions. Frankel suggested that a stiff soil site should be used as the reference, largely because of considerations from the western U.S. The definition of "rock" varies from the broken-up rock found in California to the hard rock of portions of the eastern U.S. There are also more strong-motion data in the western U.S. for sites on stiff soil than for sites on competent rock.
Several issues relevant to seismic engineering were discussed by E.V. Leyendecker (USGS), including the ground motion parameters to plot on the hazard map and what probability levels to use. Present plans are to produce probabilistic maps with peak acceleration and spectral response values at periods of 0.3 and 1.0 seconds.
The workshop attendees agreed on a three-model approach to hazard mapping in the eastern U.S., for maps with annual probabilities of exceedance of 0.001 and greater. Figure 9 shows these models. Each model represents a separate assumption about future seismicity and conserves the historically-observed rate of M5 and greater earthquakes. Model 1 (left) is based on the magnitude 3 and larger earthquakes since 1924, covering the time period of catalog completeness. These earthquakes are counted on a grid and the values on this grid are then smoothed spatially by convolving with a Gaussian function. This smoothed grid of activity values (a-values) is used to calculate probabilities of exceedance of specified ground motions for each site location of the hazard map. This method is similar to that proposed by Jacob et al. (1994) and applied to mapping seismic hazard in New York State, although the methods differ in their smoothing algorithm and grid size. Model 1 (left) basically assumes that the magnitude 3 and above events are illuminating the tectonic structures which can generate larger destructive earthquakes. By using the smoothed historical seismicity, this method avoids the need for drawing area source zones as is traditionally done to construct probabilistic hazard maps.
Model 1 (right) considers the hazard from characteristic earthquakes, that is, larger earthquakes not reflected in magnitude 3 events since 1924. Such characteristic earthquakes can be identified from paleoliquefaction studies (e.g., New Madrid, Wabash Valley, Charleston) and sometimes in the historic record (Charlevoix). The hazard from the characteristic earthquakes is added to that derived from the smoothed magnitude 3 and greater events. In the future, geodetic strain rates may also be useful in delineating hazardous areas in the eastern U.S. and these would be included in model 1.
The second model consists of magnitude 5 and larger events since about 1700. These events are also smoothed spatially. This model addresses the possibility that future damaging (M5 and larger) earthquakes will occur near past ones. Historic damaging earthquakes may be located on localized seismogenic structures which can generate future destructive earthquakes.
The third model consists of a uniform background zone. The workshop participants agreed on a uniform source zone east of the Rocky Mountains. The maximum magnitude would be determined by whether the event occurred in the craton or outside of it. This model basically assigns a water-level of seismic hazard which includes areas that have not had earthquakes historically, addressing our present lack of understanding of what causes earthquakes in the eastern United States. Thus, the three-model approach covers a broad range of hazard models, from earthquakes repeating near where they have occurred before to earthquakes occurring virtually anywhere in the central and eastern U.S. with equal probability.
Each model will be assigned a weight that sums to unity to make probabilistic hazard maps. The weights will be determined by the workshop attendees after interim maps are produced. There was also some sentiment among workshop participants for having maps with the worst case of each model plotted at each location. Some workshop participants suggested that the results of this simple three-model approach be compared with those from studies done by the Electric Power Research Institute (EPRI) and Lawrence Livermore National Laboratory, which used multiple-source zone models based on groups of experts. Subsequent to the workshop, a comparison between the three-model method and the EPRI study was done, and showed good agreement for nuclear plant sites (Frankel and Perkins, 1994).
The next step in the process of developing new seismic hazard maps is the USGS preparation of interim maps. These interim maps will be provided to workshop attendees and other interested people. The USGS will invite written comments on these interim maps. There is much work to be done and the workshop was a successful first step.
Algermissen, S.T., Perkins, D.M., Thenhaus, P.C., Hanson, S.L., and Bender, B.L., (1990), Probabilistic Earthquake Acceleration and Velocity Maps for the United States and Puerto Rico, U.S. Geological Survey Map MF-2120.
Chapman, M.C. and Krimgold, F., (1994), "Seismic Hazard Assessment for Virginia," report from Virginia Tech Seismological Observatory, Blacksburg, Virginia.
Frankel, A. and Perkins, D., (1994), Mapping Seismic Hazard for the Central and Eastern United States, abstract for Eastern Section SSA, Seismological Research Letters, in press.
Jacob, K., Armbruster, J., Barstow, N., and Horton, S., (1994), "Probabilistic Ground Motion Estimates for New York: Comparison with Design Ground Motions in National and Local Codes," Proceedings of the Fifth U.S. National Conference on Earthquake Engineering, Chicago, Illinois,, pp. 119-128.
Seeber, L. and Armbruster, J., (1991), "The NCEER-91 Earthquake Catalog: Improved Intensity-Based Magnitudes and Recuurence Relations for U.S. Earthquakes East of New Madrid," Report Number NCEER-91-0021, University at Buffalo, Buffalo, New York.
Current recommendations and guidelines for the seismic evaluation and retrofitting of highway bridges are limited to structures of conventional steel and concrete girder and box girder construction, with spans not exceeding 500 feet (150 meters). However, longer bridges, which are typically considered to be "important" or "critical" structures under most definitions of bridge importance, are not presently covered under any current codes or guidelines, and are usually evaluated or retrofitted on a case-by-case basis. Such bridges include, but are not limited to, suspension and cable-stayed bridges, arches, and long-span box girder and truss bridges. Furthermore, bridges in the 200 to 500 foot (60 to 150 meter) span range may not be adequately covered by the current FHWA recommendations for seismic retrofitting.
Many structural components incorporated into long-span bridges, like floor beams and stringers, can be evaluated and retrofitted using available criteria appropriate for those components. However, due to their very nature, the seismic evaluation and retrofitting of long-span bridges must consider structural members and details, and additional factors, that are specific to such structures. At this time, there is no clear-cut consensus as to what the most important factors and issues that must be evaluated are, and for which additional guidance may be necessary or must be developed, for these bridges.
In order to address these concerns, NCEER conducted the Long-Span Bridge Seismic Research Workshop on December 12 and 13, 1994, in San Francisco, California. The workshop was organized by Ian M. Friedland and chaired by Ian G. Buckle, both from NCEER, and was sponsored by the Federal Highway Administration as a task in the NCEER Highway Project. Thirty-six people attended the workshop, of which more than 15 were NCEER affiliates. Attendees included a mix of researchers and practitioners with experience in long-span bridge technical issues, including representatives from academia, State and Federal governments, and the consulting engineering community. The focus of this workshop was on issues unique to long "monumental" structures. Long, multi-span bridges were not of primary concern in the workshop, but were included where overlapping interests occurred (e.g., spatial variation).
Prior to the workshop, all attendees were asked to submit a list of what they considered to be the critical seismic concerns and research needs for long-span bridges. More than 160 individual concerns were identified by participants, and these were classified into six technical categories:
To kick off the workshop, overview presentations were made in each of these technical areas. Presenters included Ian Buckle, performance criteria; Klaus Jacob (Lamont-Doherty Earth Observatory), ground motion; Geoffrey Martin (University of Southern California), geotechnical; Frieder Seible (University of California at San Diego), analysis; Roy Imbsen (Imbsen & Associates, Inc.), structural details; and Charles Seim, (TY Lin International), materials/retrofit measures. Participants broke into technical working groups and further discussed, identified, and prioritized critical issues and research needs in each of these areas.
Participants then reconvened in a general session, during which the most important issues and research needs that were identified during the technical break out sessions were presented and further discussed. The top three-to-five issues in each area were then agreed upon.
A general consensus was reached on a number of critical issues and research needs. Among those considered to be the most important were the following:
Subsequent to the workshop, the top issues in each area are being further developed and drafted into research task statements by the technical area presenters. These will then be sent to all workshop participants for review and a final balloting and ranking by mail.
It is expected that the results of the workshop will be incorporated into the Year 3 and Year 4 research programs of the NCEER Highway Project, through the initiation of several tasks identified as the most critical for long-span highway bridges. In addition, the proceedings of the workshop and the results of the mail-ballot ranking of critical issues will be published by NCEER in the spring of 1995.
The Naval Facilities Engineering Command, Department of the Navy, has recently negotiated a design/build contract with NCEER to design and implement viscoelastic dampers for a Navy-owned reinforced concrete structure to provide seismic hazard reduction. The structure is Building 116, an office/supply facility located at the Naval Station, San Diego. The work under the $1.42 million contract includes the design, construction and performance monitoring of viscoelastic dampers as passive energy dissipation devices to be installed in the building and a demonstration of the feasibility of this innovative technology for seismic strengthening of similar buildings located in high seismic risk areas.
This project represents one of the implementation projects at NCEER following extensive research over the last few years in the seismic applications of viscoelastic dampers. The research involved NCEER investigators at the University at Buffalo, University of California at Berkeley, and the University of Illinois under co-sponsorship of the 3M Company of St. Paul, Minnesota. Through analysis, laboratory experiments, and full-scale structural tests, NCEER research provided information on the dynamic behavior of viscoelastic materials in the seismic environment, demonstrated the viability of incorporating viscoelastic dampers into new or existing structures for seismic hazard reduction, and developed design procedures for their use in steel-frame and concrete structures. While full-scale implementation of viscoelastic dampers to steel-frame structures has taken place (see NCEER Bulletin, Vol. 8, No. 1, 1994), the Navy project provides the first application of this innovative technology to a reinforced concrete structure.
The project team is led by Dr. T.T. Soong, principal investigator; Dr. A.M. Reinhorn, faculty associate; and Dr. Keling Shen, research associate. The Crosby Group of Redwood City, California, has been designated as the architectural/engineering firm to provide analysis, design, and construction support. The construction firm is Douglas E. Barnhart, Inc. of San Diego, California. The 3M Company is also contributing to the project by providing technical support and viscoelastic dampers at a significantly reduced cost. The project is expected to be completed in 42 months.
NCEER technical reports are published to communicate specific research data and project results. Reports are written by NCEER-funded researchers, and provide information on a variety of fields of interest in earthquake engineering. The proceedings from conferences and workshops sponsored by NCEER are also published in this series. To order a report reviewed in this issue, fill out the order form and return to NCEER. To request a complete list of titles and prices, contact NCEER Publications, University at Buffalo, Red Jacket Quadrangle, Box 610025, Buffalo, New York 14261-0025, phone: (716) 645-3391; fax: (716) 645-3399; or email: email@example.com.
3D-BASIS-TABS: Version 2; Computer Program for Nonlinear Dynamic Analysis of Three Dimensional Base Isolated Structures
A.M. Reinhorn, S. Nagarajaiah, M.C. Constantinou, P. Tsopelas and R. Li, 6/22/94, NCEER-94-0018, 168 pp., $15.00
This report describes the development of computer program 3D-BASIS-TABS, Version 2.0. The new program is an enhanced version of 3D-BASIS-TABS. The report should be viewed as a continuation and addition to previous reports NCEER-93-0011 and NCEER-91-0005. The enhancements that are documented in this report include: 1) addition of new isolation elements; 2) models of nonlinear dampers and other hysteretic elements; 3) additional verification; 4) addition of several new example problems; 5) new input/output format for easier usage; and 6) updated user's manual.
Development of Reliability-Based Design Criteria for Buildings Under Seismic Load
Y.K. Wen, H. Hwang and M. Shinozuka, 8/1/94, NCEER-94-0023, 172 pp., $15.00
The design of buildings and structures for seismic loads are traditionally based on the performance of structures in past earthquakes. Although the large uncertainty in the earthquake loadings has long been recognized by engineers, it has not been fully accounted for in code procedures other than in the selection of a design earthquake. Since the design earthquake is used in conjunction with a series of factors to account for effects of structural period, site soil condition, inelastic behavior, importance of structures etc., the reliability and safety of the final design remains unknown and undefined. The recent sentiment of the research community and design professionals is that there is a need for development of design procedures based on consideration of the physics of the problem and explicit treatment of the uncertainties. Such procedures may be used as the basis for development of the next generation of buildings codes. In this report, the theory and methodology that can be used to formulate such a design procedure is presented. A brief review is given of the theoretical background of reliability analysis and reliability-based design, followed by an examination of the safety considerations in representative current code procedures as well as the reliability of buildings designed in accordance with such procedures in different countries. Finally, a bi-level, performance-based design procedure is proposed in which desirable reliabilities can be implemented against both unserviceability and ultimate failure.
Experimental Verification of Acceleration Feedback Control Strategies for an Active Tendon System
S.J. Dyke, B.F. Spencer Jr., P. Quast, M.K. Sain, D.C. Kaspari Jr. and T.T. Soong, 8/29/94, NCEER-94-0024, 102 pp., $15.00
Most of the current active structural control strategies for aseismic protection have been based on either full-state feedback (i.e., structural displacements and velocities) or velocity feedback alone. However, accurate measurement of the displacements and velocities is difficult to achieve directly, particularly during seismic activity, since the foundation of the structure is moving with the ground. Because accelerometers can readily provide reliable and inexpensive measurements of the structural accelerations at strategic points on the structure, development of control methods based on acceleration feedback is an ideal solution to this problem. The purpose of this report is to demonstrate experimentally that stochastic control methods based on absolute acceleration measurements are viable and robust, and that they can achieve performance levels comparable to full-state feedback controllers.
The Fall/Winter season has been a busy one for the NCEER Information Service. In September, an exhibit was presented at the New York State Disaster Pre-paredness Conference in Albany, New York, as well as the Annual Convention of the Structural Engineers Association of California (SEAOC), held in Lake Tahoe, California. In December, Information Service staff participated in a panel at the Northridge Earth-quake Research Conference in Los Angeles and hosted an exhibit. Finally, in January, exhibits were hosted at a course on the Static and Seismic Slope Stability for Wave Containment Facilities in Saratoga Springs, New York, and at the Northridge Earthquake: One Year Later Conference, held in Universal City, California.
Patricia Coty, Manager of the Information Service, has taken a medical leave of absence. Dorothy Tao and Carol Kizis are filling in for Pat while she is recuperating.
As reported in the NCEER Bulletin (Vol. 8, No. 3, July 1994), NCEER has established a Gopher on the Internet. The Gopher provides access to many resources of interest to the earthquake hazard mitigation community. To connect to the NCEER Gopher, type the following command at your local system prompt:
gopher nceer.eng.buffalo.edu <enter>
The root menu will appear next. The root menu provides access to other menus or documents which can be viewed through the Gopher (see figure 1). The following paragraphs briefly describe each selection option on the Gopher root menu.
<menu> About Earthquakes
<document> About NCEER
<document> About the NCEER Gopher Server
<document> Comprehensive Listing of Professional Meetings
<menu> Connect to NCEER FTP
<menu> Connect to Other Gophers
<menu> Federal, State and Local Programs
<document> NCEER Information Service Resources
<menu> Other Earthquake Related FTP's
<menu> QUAKELINE® Database
<menu> Veronica Searches (search items in gopherspace)
<document> Who to Contact for Help
<menu> NCEER Earthquake Engineering Highway Project
Figure 1: NCEER Gopher Root Menu.
This selection offers two menus: Earthquake Engineering and Earthquake Fundamentals. Earthquake Engineering contains three documents:
Earthquake Fundamentals contains two papers:
This document provides a description of NCEER's mission and purpose.
About the Gopher Server
This document contains a description of the Gopher, what it contains, who to contact for additional information or to provide comments, and where the server is located.
Comprehensive Listing of Professional Meetings
This document provides a listing of professional meetings of interest to the earthquake hazard mitigation community. The document is updated monthly.
Connect to NCEER ftp
This menu affords the user the ability to connect to NCEER's anonymous ftp (file transfer protocol) site (see NCEER Bulletin, Vol. 8, No. 2, April 1994). The ftp site contains a wealth of information mostly provided by NCEER, and the Gopher allows easier access to this information than logging onto the ftp site directly. A brief description of the information contained in the ftp site follows:
Search NCEER Information Service Search List - this item is currently not operational.
NCEER Anonymous ftp
- grndmotion - this selection provides information on obtaining copies of strong ground motion records from other organizations, online systems or CD-ROM.
- infsvr_news - this selection allows access to the past six issues of the Information Service News.
- nceer_descrip and nceer_de.scrip - these documents provide a description of NCEER's mission and purpose.
- orders - this selection contains order forms for publications, including single-title, subscriptions and exchange agreements.
- reports - this selection contains a list of NCEER technical reports, abstracts from all NCEER technical reports, a price list for NCEER technical reports, and a subject index for NCEER technical reports.
- schlprog - this selection contains two papers related to earthquake education issues: "Earthquake Preparedness: The School Bus Driver" by C. Martens of the Earthquake Preparedness Council and "Planning for the Psychological Aftermath of School Tragedy" by Thomas Frantz of the University at Buffalo.
- searches - this selection contains computer searches performed by the Information Service staff from 1991 through 1994.
- software - this selection provides access to the 3D-BASIS and IDARC (pcversion) computer programs in executable form.
- wind - this selection contains issues of the Wind Engineer, published periodically by the Wind Engineering Research Council.
Directory of Available Searches - this selection provides a listing of computer searches performed by Information Service staff from January 1991 to the present.
Additional Site for NCEER and Earthquake Engineering Software and Data - this selection is not yet operational.
Connect to Other Gophers
This selection allows access to other gophers with information that pertains to the earthquake hazard mitigation community. They are:
Emergency Preparedness Information Exchange (EPIX) - dedicated to the promotion of networking in support of disaster mitigation research and practice.
National Science Foundation Gopher - part of NSF's Science and Technology Information System (STIS) which allows access to publications, award abstracts and other pertinent information.
Newcastle Earthquake Database
SUNY-Buffalo Engineering Gopher (Venus) - contains a variety of items from the School of Engineering at the University at Buffalo, including calls for papers, software and news items.
SUNY-Buffalo Gopher (Wings) - campus wide information system for the University at Buffalo. Contains information about the University, and its services for students, faculty, staff and other interested parties.
U.S. Geological Survey Gopher - provides general information about the USGS and its divisions, publications and data; its network of resources; and other geology, hydrology, cartography and GIS information.
NISEE Earthquake Information Gopher - provides a link to available information services in earthquake engineering, earthquake hazard mitigation, earthquake disaster response and other related disciplines.
USAID Gopher - facilitates distribution of the U.S. Agency for International Development information to the public, including administrative information, development efforts, Congressional presentations, procurement and business resources, publications and other development-related Internet resources.
Federal, State and Local Programs
This selection contains two menus: Government Agency Activities and NEHRP Programs. The first selection contains a paper entitled "U.S. Activities on Natural Disaster Reduction: U.S. Government Agencies," compiled by the U.S. government agencies subcommittee on natural disaster reduction for the World Conference for Natural Disaster Reduction, held in Yokohama, Japan on May 23-27, 1994. The other selection contains a paper taken from "NEHRP Five Year Plan for 1989-1993" and describes the background, purpose, programs, principal agencies and program structure of NEHRP.
NCEER Information Service Resources
This selection provides a general description of services provided by the NCEER Information Service. These include reference support, the QUAKELINE® database, Information Service News, the anonymous ftp site and the Gopher.
Other Earthquake Related ftps
This item allows the user to telnet to NCEER's STRONGMO database at Lamont-Doherty Earth Observatory and to the USGS's anonymous ftp site.
QUAKELINE® is a bibliographic database developed and supported by the NCEER Information Service. Users can telnet directly into QUAKELINE® from this menu selection.
This selection allows access to the NYSERNet gopher.
Who to Contact for Help
This selection provides the name and address of who to contact with questions, comments, suggestions and contributions of material for the NCEER Gopher.
NCEER Earthquake Engineering Highway Project
This selection contains two papers: "The Highway Project at the National Center for Earthquake Engineering Research" by Ian. G. Buckle and Ian M. Friedland; and "A Seismic Retrofitting Manual for Highway Bridges" by Ian G. Buckle, Ian M. Friedland and James D. Cooper.
This selection contains a paper entitled "The Nature of Wind" prepared by the Panel on the Assessment of Wind Engineering Issues in the United States, and the Wind Engineer, a newsletter published by the Wind Engineering Research Council.
The Fifth Mallet-Milne Lecture, "From Earthquake Acceleration to Seismic Displacement" will take place May 24, 1995 at 5 p.m. at the Institution of Civil Engineers, 1-7 Great George St., London, SW1P 3AA. The lecture will be given by Professor Bruce A. Bolt of the University of California at Berkeley. The event is sponsored by the British Geological Survey and tickets can be obtained by contacting the secretary of the Society for Earthquake and Civil Engineering Dynamics at (0171) 839-9827 or by writing to the Institution of Civil Engineers at the above address.
The Fifth SECED Conference on European Seismic Design Practice - Research and Application will be held October 26-27, 1995 in the United Kingdom. The conference will provide a forum for discussion and exchange of information on the status of seismic design practice in Europe and the research activities related to code development. For more information, contact Rachel Coninx, The Conference Office, Institution of Civil Engineers, One Great George Street, London, SW1P 3AA, U.K., phone: (+44) (0) 71 839-9807; fax: (+44) (0) 71 233-1743.
Candidates are currently being solicited for the 1995 Shamsher Prakash Research Award. The award is presented to a young researcher or scientist specializing in geotechnical engineering. The award is $1,000.00. Applications/ nominations should include the following information: name of the candidate, complete postal address and telephone/fax number/e-mail address, date of birth, chronology of education, chronology of jobs held, area of specialization, complete list of refereed publications in journals (please include at least five significant publications), statement of process developed and patents, if any, a statement of 500 words of significant contributions in the past five years and potential of future contributions (on a separate sheet), and any other relevant information.
Previous winners include: 1994 - Manuel Pastor (Spain) and Susumu Iai (Japan); 1993 - Dennes T. Bergado (Thailand) and Shobha K. Bhatia (USA); 1992 - R. Kerry Rowe (Canada); 1991 - None; 1990 - George Gazetas (USA/ Greece).
Nominations must be submitted by May 31, 1995. Please send seven complete application sets to: Sally Prakash, Honorary Secretary, Shamsher Prakash Foundation, Rolla, Missouri 65401, phone: (314) 364-5572, fax: (314) 364-5572 (*51); or email: firstname.lastname@example.org.
CUREe, California Universities for Research in Earthquake Engineering, is soliciting announcements of research projects underway as a result of the Northridge, California earthquake of January 17, 1994. With FEMA funding, CUREe organized the Conference on Northridge Earthquake Research Coordination held in Los Angeles December 2 and 3, 1994, at which the first draft of the "Directory of Northridge Earthquake Research" was released. A revised version will be produced in early 1995.
To have a research project included in the revised directory, please send a one-page summary of the project, the names of the co-principal investigators or consultants involved in the effort, and the following information on the principal investigator or person in charge of the project: name, address, telephone number, facsimile number, e-mail, and small photo (such as a passport photo). In addition to individual research projects, listings for compilations of government or other data, maps, reports, and libraries and information services will also be included in the directory.
To submit a one-page camera-ready summary and related information, or to order a copy of the directory, write to CUREe, Northridge Research Coordination Project, 1301 South 46th St., Richmond, CA 94804, phone: (510) 231-9557; fax: (510) 231-5664.
National Center for Earthquake Engineering Research
State University of New York at Buffalo
Red Jacket Quadrangle
Buffalo, NY 14261-0025
Phone: (716) 645-3391
Fax: (716) 645-3399
Editor: Jane Stoyle
Associate Editor: William Wittrock
Illustration and Photography: Hector Velasco
Production and Mailing List: Laurie McGinn
J. Benavides, The Pennsylvania State University
R. Dobry, Rensselaer Polytechnic Institute
A. Frankel, U.S. Geological Survey
I. Friedland, NCEER
K. Jacob, Lamont-Doherty Earth Observatory
L. Liu, Rensselaer Polytechnic Institute
A. Reinhorn, University at Buffalo
A. Rose, The Pennsylvania State University
D. Tao, NCEER Information Service
P. Thenhaus, U.S. Geological Survey
T.T. Soong, University at Buffalo
Some of the material reported herein is based upon work supported in whole or in part by the National Science Foundation, the New York State Science and Technology Foundation, the U.S. Department of Transportation and other sponsors. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of NCEER or its sponsors.