Reconnaissance Report of the May 28, 2009 Honduras Earthquake, M 7.3

A team sponsored by the Earthquake Engineering Research Institute (EERI) and the Geoengineering Extreme Event Reconnaissance (GEER) Association carried out a field investigation in conjunction with Honduran colleagues from June 18-23 to document effects of the May 28 earthquake. The EERI-GEER team was invited by Mr. Marco Sandoval, Executive Director of the Comisión Ejecutiva Valle de Sula (CEVS). Mr. Sandoval sent a team of engineers to accompany the EERI-GEER team. The team included experts in structural, geotechnical engineering, as well as in disaster response and recovery. The investigators were supported by EERI: Abdeldjelil Belarbi and GEER: Ronaldo Luna and Kermit Applegate, all from Missouri S&T, Rolla. The CEVS team consisted of Humberto Calderon, Osvaldo Rivera, and Luis Alonso Lopez. Observations of other individuals who visited the earthquake-affected region have also been incorporated in this report. This material is based upon work supported by the National Science Foundation through the GeoEnvironmental Engineering and GeoHazards Mitigation Program under Grant No. CMMI-0825734. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. The GEER Association is made possible by the vision and support of the NSF Geoenvironmental Engineering and GeoHazards Mitigation Program Directors: Dr. Richard Fragaszy and the late Dr. Cliff Astill. GEER members also donate their time, talent, and resources to collect time-sensitive field observations of the effects of earthquakes. The EERI efforts were supported through the Learning From Earthquakes (LFE) program which is also funded by the National Science Foundation

Evaluation of the Taum Sauk Upper Reservoir Failure

The Taum Sauk Upper Reservoir was built in the early 1960’s as a water storage reservoir for hydro-electric energy production. The reservoir was created by blasting rock from the top of Proffit Mountain. The rock debris generated was then used to construct a kidney shaped earthen embankment atop the mountain. The reservoir is located in Reynolds County near the town of Lesterville, Missouri. The Upper Reservoir was approximately 95 feet in depth and covered a surface area of roughly 55 acres. The reservoir had the capacity to hold nearly 1.5 billion gallons of water. The Upper reservoir underwent a catastrophic failure on the morning of December 14th, 2005 releasing most of its stored water down the northwest side of Proffit Mountain. An approximate 700-feet wide breach occurred along the northwest radius of the rock-fill dike, causing severe damage to state park property. No fatalities resulted from the failure events. This paper evaluates different failure mechanisms of the reservoir based on three distinct failure hypotheses. Conclusions are then made based on the analyses and discussion of each mechanism, categorized in terms of the likely contribution to the Taum Sauk Upper Reservoir failure

Liquefaction Effects on Lateral Pile Behavior for Bridges

A coupled pile-soil-structure interaction (SPSI) analysis method is presented to study the liquefaction effects on lateral pile behavior of the highway bridges. Pile-soil interaction is simulated by the dynamic nonlinear p-y method including the effect of liquefaction. The liquefaction effects to the pile-soil interaction are taken into account by introducing a degradation multiplier to the p-y curve. The degradation multiplier is related to the excess pore water pressure buildup at the pile-soil interface. The SPSI analysis method is implemented into a Missouri highway bridge site near the New Madrid Seismic Zone (NMSZ) rift complex for future earthquake scenarios of Mw 7.0. Synthetic motions at rock base were developed to the bridge foundation level for SPSI analyses. Results from analysis indicate that the degradation of p-y curve due to the excess pore water pressure significantly increases displacement of superstructure and moment of pile foundation

Nonlinear Site Response Analysis in the New Madrid Seismic Zone

Deep alluvial soil deposit of the Mississippi Embayment overlies the New Madrid Seismic Zone. A new nonlinear site response analysis model has been developed for wave propagation in deep soil deposits. The shape of the backbone curve of the model is described by the empirical unified formulas. Extended Masing criteria are used to represent hysteretic loading and unloading of soils. The new model takes into account the influence of the effective confining pressure on the shear modulus degradation and the viscous damping development in soil. The model is implemented into a two-dimensional finite element code in the time domain and calibrated with the recorded motion at Treasure Island during Loma Prieta Earthquake (1989). Results show that this model provides an acceptable outcome with simple input parameters. Finally, the new model is implemented into the site response analysis at a Missouri highway bridge site. The results show that the influence of the confining pressure is significant for the site response analysis of deep soil sediments

Impact of Geographical Information Systems on Geotechnical Engineering

Over the last four decades Geographical Information Systems (GIS) have emerged as the predominant medium for graphic representation of geospatial data, including geotechnical, geologic and hydrologic information routinely used by geotechnical and geoenvironmental engineers. GIS allow unlimited forms of spatial data to be co-mingled, weighted and sorted with any number of physical or environmental factors. These data can also be combined with weighted political and aesthetic values to create hybrid graphic products capable of swaying public perceptions and decision making. The downside of some GIS products is that their apparent efficacy and crispness can also be deceptive, if data of unparalleled reliability is absorbed in the mix. Disparities in data age and quality are common when compiling geotechnical and geoenvironmental data. Despite these inherent shortcomings, GIS will continue to grow and evolve as the principal technical communication medium over the foreseeable future and engineers will be forced to prepare their work products in GIS formats which can be widely disseminated through the world wide web. This paper presents the historical evolution of GIS technologies as it relates to the impact in geotechnical engineering, concluding with four case histories on the application of this emerging technology

Recent Geotechnical Developments in Geospatial Information Systems Technology

Geotechnical engineering projects in current research and practice are increasingly undergoing geospatial analysis based on geologic and geotechnical data collected. The explosion of spatial data that is available for surface features, particularly from the raster based products, heavily used by commercial and available to the public, present only one dimension of site characterization. Geotechnical engineers are more interested in data with depth immediately below their project site retrieve from drilled and imaged subsurface surveys. The ability to optimize the use of new and existing subsurface data continues to be undermined by the lack of a common and agreed data format and structure. Over the past decade several initiatives have tried to develop some consensus, with limited success. The latest initiative for a common geotechnical data exchange standard is also described. Several projects based on the authors, experience are featured in this paper and serve as examples of the challenge of working with large and diverse subsurface geotechnical databases. Additionally, an update of a geotechnical data exchange format is also presented to point the direction for the future

Deformation Analysis of Missouri Bridge Approach Embankments

Missouri has recently experienced below expectation performance or the bump-at-the-end of the bridge phenomena at bridge approach slab transitions. Information on approach slab performance was collected state wide to assess if the problem was limited to regional or geological distribution. Finite element analysis was then used to explore the soil embankment-bridge structure differential settlement in two Missouri bridges; MoDOT Bridge A6031 in Livingston County, and MoDOT Bridge A5834 in Pulaski County. These two cases are indicative of the types of soil conditions encountered in the Northern Glaciated Plains region (deeper compressible foundation soils) and the Southern Ozarks region (shallow rocky clays) of Missouri. The construction sequence was tied to the analysis by applying the embankment and slab loading following the construction records. The finite element method results compared well with observed displacements. Recommendations for construction sequence are provided

Transverse-Earthquake Induced Deformations of a Bridge Approach Embankment in the New Madrid Seismic Zone

It is predicted that strong earthquakes, larger than M 7.0, may occur within next 50 years in the New Madrid Seismic Zone (NMSZ), the location of three of the most powerful earthquakes in United States history. Large displacements may occur during strong earthquakes that can cause an embankment to fail or lose its function. The hyperbolic stress-strain model with Masing rules was modified to account for strength and stiffness reduction due to change in the effective confining pressure. The Byrne model was combined with a hyperbolic model to calculate the pore water pressure caused by seismic shaking. This modified hyperbolic model was implemented into the computer code, FLAC, and calibrated against the 1971 Upper San Fernando Dam failure. It appears that the modified model is superior to the built-in Finn model in FLAC to predict the earthquake-induced deformation of the embankments. Then it was applied to study the seismically induced deformation of an approach embankment to Bridge A1466 in the NMSZ near Hayti, Missouri

A Slurry Consolidation Approach to Reconstitute Low-Plasticity Silt Specimens for Laboratory Triaxial Testing

Silt Specimen Reconstitution using a Slurry Consolidation Approach is Commonly Used for Laboratory Testing. This Paper Presents a New Slurry Consolidation Approach to Reconstitute Silt Specimens for Use in Triaxial Testing. Silt Specimens Were Reconstituted in a Split Vacuum Mold Mounted on a Special Experimental Setup. the Uniformity of the Reconstituted Specimens Was Verified by Measuring the Water Content and Grain Size Distribution throughout the Specimens. the Testing Program Was Expedited using a Special Sample Handling Technique to Move the Specimen from the Special Experimental Setup to the Triaxial Chamber Base Platen. the Handling Process Did Not Disturb the Specimens to a Measurable Degree. Further, the Replicas of the Reconstituted Specimens Were Verified by Submitting Them to Basic Volumetric Measurements Followed by Static and Cyclic Triaxial Tests. the Triaxial Test Results Reported Very Small Differences. Copyright © by ASTM Int\u27l (All Rights Reserved)