Geotechnical Engineering Commons^™

Scale Model Shake Table Testing Of Seismic Earth Pressures In Soft Clay, Ron Edward Noche

Master's Theses

This research consists of scale model shake table tests to investigate the development of seismic earth pressures in soft clay. The soft clay was modeled after prototype San Francisco Bay Mud consisting of a mixture of kaolinite, bentonite, class C fly ash and water. A flexible walled testing container founded on a 1g shake table was used to house the model soil and mimic 1D site response. An array of accelerometers embedded in the model soil measure during an input earthquake motion.

A scale model wall is equipped with pressure sensors to measure the seismic earth pressures over the duration …

Effects Of Waste Placement Practices On The Engineering Response Of Municipal Solid Waste, Jason Taylor Cox

Master's Theses

An extensive laboratory and field investigation was conducted at Santa Maria Regional Landfill (SMRL) in Santa Maria, CA to determine the effects of waste placement practices on the engineering response of municipal solid waste (MSW). Laboratory and field testing was used to determine the engineering properties and monitor field response of MSW.

The specific gravity (G_s) of manufactured MSW (MMSW), fresh MSW (FMSW), and old MSW (OMSW) was determined experimentally using a modified version of standard soil testing procedures. Effects of particle size, compactive effort, and degradation on the specific gravity of waste were evaluated. Specific gravity …

One-Dimensional Compressibility Of Intermediate Non-Plastic Soil Mixtures, Sean E. Salazar

Civil Engineering Undergraduate Honors Theses

The results of high stress, one-dimensional compression testing on intermediate soils are presented. Nevada Sand and silica silt mixtures were subjected to very high vertical stresses (140 MPa) in one-dimensional, monotonic compression. Each soil mixture was tested in a nominally loose condition. A specially designed mold with an integrated sensor array was fabricated to contain the soil during pre-consolidation and loading. The 1-D compression curve was plotted for each mixture in the double-logarithmic void ratio (e), and vertical effective stress (σ’v) space and characteristics of the Limiting Compression Curve (LCC) were identified. Initial and post test grain size distribution curves …

Characterization Of Fractures Subjected To Normal And Shear Stress, Min-Kwang Choi

Open Access Dissertations

Results from a series of laboratory experiments to determine fracture specific stiffness, for a fracture subjected to shear and normal stress, are presented and analyzed. The experimental work focuses on the determination of relations between normal and shear fracture specific stiffness and between spatial distribution of fracture specific stiffness and fluid flow through the fracture

The ratio of shear to normal fracture specific stiffness is experimentally investigated on a fracture subjected to shear as well as normal stress. Synthetic fractures made of gypsum and lucite were prepared with different fracture surface conditions: either well-mated or non-mated. For well-mated fracture surfaces, …

Triclosan Enriches For Dehalococcoides-Like Chloroflexi In Anaerobic Soil At Environmentally Relevant Concentrations, Patrick J. Mcnamara, Mark J. Krzmarzick

Civil and Environmental Engineering Faculty Research and Publications

Triclosan is an antimicrobial agent that is discharged to soils with land-applied wastewater biosolids, is persistent under anaerobic conditions, and yet its impact on anaerobic microbial communities in soils is largely unknown. We hypothesized that triclosan enriches for Dehalococcoides-like Chloroflexi because these bacteria respire organochlorides and are likely less sensitive, relative to other bacteria, to the antimicrobial effects of triclosan. Triplicate anaerobic soil microcosms were seeded with agricultural soil, which was not previously exposed to triclosan, and were amended with 1 mg kg⁻¹ of triclosan. Triplicate control microcosms did not receive triclosan, and the experiment was run for …

Initial Elastic Modulus Degradation Using Pressuremeter And Standard Penetration Test Results At Two Sites, Dustin Robbins

UNLV Theses, Dissertations, Professional Papers, and Capstones

In-situ testing was performed at two sites consisting of pre-bored pressuremeter testing, seismic surface wave testing to develop a shear wave velocity profile, and Standard Penetration testing during the soil boring phase in order to evaluate the feasibility of using large shallow foundations for a project. This study focuses on a comparison of the in-situ direct measurements of soil stiffness obtained from this testing program. The small strain modulus obtained from the seismic surface wave test results is compared to the intermediate strain modulus obtained from both the initial loading pressuremeter modulus and reload pressuremeter modulus. The modulus calculated from …

Army Corps Of Engineers, U.S., Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of how the U.S. Army Corps of Engineers has influenced historical and contemporary economic, environmental, and political developments in the American West.

Analysis Of Aggregate Distribution In Self-Consolidating Concrete, Brendan Ho

Civil Engineering Undergraduate Honors Theses

Concrete consists of several key ingredients: cement, water, and coarse and fine aggregate. Depending on the proportions of these ingredients, the strength and workability of a concrete mix can be affected adversely. Segregation is the separation of aggregate and cement paste, resulting in a lack of homogeneity. Self-consolidating concrete (SCC) does not require traditional consolidation; however, it can be affected by segregation. This project examines different SCC mixtures and establishes ranges of values for slump flow, T20 , Visual Stability Index (VSI), J-ring flow and J-ring flow spread that ensures proper aggregate distribution and therefore reduces the potential of segregation. …

Case Histories Of Liquefaction In Loose Sand Fills During The 1989 Loma Prieta Earthquake: Comparison With Large Scale And Centrifuge Shaking Tests, Ricardo Dobry, Tarek Abdoun, Sabanayagam Thevanayagam, Hesham El-Ganainy, Vicente Mercado

International Conference on Case Histories in Geotechnical Engineering

The paper focuses on loose clean and silty sand fills that liquefied during the 1989 Loma Prieta, California earthquake. Available field case histories of liquefaction that include measured shear wave velocity from the Andrus et al. (2003) database are used. The liquefaction behavior observed in these field case histories is compared with the results of two large scale and six centrifuge shaking tests conducted by the authors. System identification and site response analyses are used to obtain the corresponding cyclic shear stress ratios in the tests. Due consideration is given to the shaking duration and 1D versus 2D shaking in …

Sustainability And Waste Management: Case Histories, Hari D. Sharma

International Conference on Case Histories in Geotechnical Engineering

Sustainability is the condition of maintaining a process or a state at a certain level for perpetuity. In waste management and geoenvironmental engineering terms: sustainability is making marginal and waste lands and waste products into usable properties, products and services. To address sustainability issue, this paper first presents waste minimization policies prior to disposal; a few examples of this are: recycling, composting and incineration. After efficiently using the waste minimization policies, the remaining produced waste needs to be disposed of which has two aspects (i) the presently active waste disposal sites and (ii) the already disposed waste and closed waste …

Use Of Porous Concrete And Scoria Bases To Clean Groundwater Recharge, Kevin T. Harker, James Mahar

International Conference on Case Histories in Geotechnical Engineering

The City of Pocatello, Idaho does not currently treat its storm water, but rather collects runoff in detention basins or discharges it into the Portneuf River. Nitrates from fertilizers and petroleum products enter local waterways and ultimately groundwater supplies. Porous concrete is regarded as a green product and has storm water filtering capabilities. Idaho State University (ISU) has been studying the use of scoria (vesicular basalt) to retain petroleum contaminants which migrate through porous concrete collection systems placed on driving surfaces. At present, ISU is conducting laboratory experiments using a physical model consisting of a porous concrete slab made with …

General Report - Session 8, Dhirendra S. (Sax) Saxena, Ram D. Singh, Rutuparna Joshi, Prashanth Vaddu

International Conference on Case Histories in Geotechnical Engineering

This General Report presents a summary of the eleven (11) papers accepted for the session 8 focused on Case History of Forensic-Geotechnical Engineering and Case Histories on Health Monitoring and Retrofit of Infrastructure. The session includes discussion of Reliability of Codes; Risk Analysis Pertaining to Public Structures, Non-Destructive Evaluation and Load Testing of Drilled Shafts, Auger Cast Piles and Driven Piles, and Damage Evaluation; Advance Information, Systems in the Geotechnical Risk Predication and Assessment. The papers originate from eight countries and cover an array of important topics in the area of forensic and geotechnical engineering. These include case histories; geotechnical-forensic …

Keynote Address, W. D. Liam Finn, Guoxi Wu

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Exhibitors, Multiple Participants

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Importance Of Observational Method In View Of Numerical Analyses For Retaning Structures In Soft Soils, Patrick Becker

International Conference on Case Histories in Geotechnical Engineering

The soil-structure-interaction of retaining structures is complex and dependent on many factors. In particular excavations in soft soils and urban environments with adjacent buildings are always subjected to deformations which are not fully avoidable. Therefore, numerical analyses can be a powerful tool for predicting the stress path and time dependent deformation behavior of retaining structures in soft soils. But the quality of these numerical predictions is directly related to the used constitutive soil models, the estimation of their material parameters and a realistic simulation of the soil-structure-interaction. The fact that Class-A predictions of the deformation behavior of retaining structures in …

Analysis Of Plie Raft Interaction In Sand With Centrifuge Tests, Donggyu Park, Doohyun Kyung, Kyujin Choi, Junhwan Lee

International Conference on Case Histories in Geotechnical Engineering

In the conventional design for piled rafts, the load capacity of the raft is not in general taken into account and the load capacity of piles is only considered for the estimation of the total load carrying capacity of the piled rafts. As a consequence, piled rafts are often designed with excessively conservative safety margin, raising a need of further investigation of the load capacity mechanism of piled rafts. In this study, a series of centrifuge load tests using model group piles and piled rafts are conducted and used to compare the axial load carrying behaviors of group piles and …

Sally Prakash: Program Director, Spouse Program, Sally Prakash

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Ahmed Elgamal: Short Curriculum Vitae, Ahmed Elgamal

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Braced Sheet Pile Shoring Wall In Sensitive Clay, Yadav Pathak, Marc Sabourin, Brian Hall, Jake Brucker

International Conference on Case Histories in Geotechnical Engineering

This case history describes the design and performance of a temporary braced sheet pile shoring wall constructed within the median between heavily-trafficked lanes of the Trans Canada Highway in Langley near Vancouver, British Columbia, Canada. The excavation extended to 9.7 m depth below the existing road grade into soft, high plasticity, sensitive glaciomarine clay. Glaciomarine clay is locally notorious for excavation and embankment stability and foundation settlement problems. The shored excavation was required to provide an access pit to allow the installation of a 3 m diameter steel pipe culvert by Horizontal Pile Driving (HPD). The braced sheet pile wall …

Base Grouting Case Studies Including Full Scale Comparative Load Testing, Jon Sinnreich, Robert C. Simpson

International Conference on Case Histories in Geotechnical Engineering

Base grouting is becoming more widely promoted in the drilled shaft industry as a means to improve shaft response to load. There are a limited number of full-scale field comparisons of test shafts which have been base grouted and adjacent test shafts which have not. This paper presents several case histories of full-scale static load test shafts as well as the results of the tests conducted on adjacent shafts with and without base grouting. The paper compares six pairs of adjacent grouted and ungrouted shafts on 5 separate projects in various parts of the United States. All tests were performed …