Geotechnical Engineering Commons^™

Investigation Of Parameters Influencing Reverse Fault Rupture Propagation To The Ground Surface, Kevin V. Stanton

Master's Theses

Surface fault rupture poses a serious threat to infrastructure in many seismically active regions, but knowledge about the factors which control the likelihood of surface displacement is limited. Current probabilistic frameworks rely only on fault mechanism and moment magnitude to predict the probability of rupture to the ground surface. However, recent work has shown that there may be other parameters which also deserve consideration. For example, statistical analyses have demonstrated that variation in near surface material stiffness may significantly affect the probability of surface rupture over reverse faults. In addition, numerical investigations indicate that the rupture history of native soil …

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 …

Sodhana Environmental - Final Design Report, Eric Taylor, Corissa Bellis, Cody Perez, Cameron Zeller

Mechanical Engineering

A fully designed cost-effective, sustainable, toilet for the developing world.

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 …

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 …

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. …

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.

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 …

Evaluation Of Liquefaction Potential Of An Earth Dam Foundation Using In Situ Tests, Ikram Guettaya, Mohamed Ridha El Ouni

International Conference on Case Histories in Geotechnical Engineering

This paper presents a case study of liquefaction potential assessment carried out under an earth dam foundation in Tunisia. An emphasis was made on the exploration of geotechnical conditions and the interpretation of field tests results collected before and after soil densification using the vibrocompaction technique. The assessment of soil liquefaction susceptibility was made using deterministic and probabilistic simplified procedures developed from several case histories. Conclusively, the obtained results show that before vibrocompaction the soil was prone to the liquefaction hazard. However, after vibrocompaction, a significant improvement of the soil resistance reduces the liquefaction potential of the sandy foundation. Indeed, …

An Investigation On The Stack Vibrations And Geotechnical Rehabilitation Solutions Case-Study: Khangiran Gas Refinery, Hadi Ghodrat, Abolfazl Yazdinejad, Javad Hosseini Masum, Mehdi Barjini Khabbaz, Arsalan Ghahramani

International Conference on Case Histories in Geotechnical Engineering

The 75 (m) high stacks of the sulfur recovery units of Khangiran Gas Refinery in Iran exhibited significant levels of vibration in winds. Field observations reported that vibration occurred in the stacks 9 times during reel years. The longest vibration duration is 8 hours and maximum tip deflection is 1 (m). In most intensive vibration occurrence much amount of water exits from around of foundation and some crack is created in the structure. Stack diameter is 4.57 (m) at the bottom and 3.43 (m) at the top and its total weight is 182.3 (Ton). The octagonal foundation diameter is 14 …

Ground Improvement For The Smithland Hydroelectric Project, Thomas Andrews, Lin Zhao, Luling Yang, Abid Mirza

International Conference on Case Histories in Geotechnical Engineering

American Municipal Power is developing the Smithland Hydroelectric Project adjacent to the U.S. Army Corps of Engineers’ existing Smithland Locks and Dam on the Ohio River. The site geology is characterized by over 100 feet of variable alluvial deposits overlying karstic limestone. The investigation program revealed loose to medium dense sands and sandy gravels along with some interbedded clay. Large voids were encountered in rock and ground loss into solution features was believed to have created ‘chimneys’ of loosened soil. A project-specific seismic hazard evaluation determined that the maximum credible earthquake (MCE) is a 7.5M event associated with the New …

Estimation Of Site Effects In The Iranian Plateau Using The Quarter-Wavelength Method, Mohammad Ebrahim Fakhimnia, Hamid Zafarani, Shima Shams Rad

International Conference on Case Histories in Geotechnical Engineering

The characteristics of strong ground motion at a given site depend upon the source mechanism, the transmission path together with the geological characteristics of source to the site, and the local soil conditions at the site, mostly known in the engineering and seismological literature as site effects. In the context of the stochastic simulation methods (e.g. Boore 1983), site effects play a significant rule in ground-motion studies. The objective of this paper is the assessment of site effects (both crustal amplification and near surface attenuation) in the Iran plateau. The effects in different parts of Iran were estimated based on …

Experimental Investigation Into Natural Base Isolation System For Earthquake Protection, Srijit Bandyopadhyay, Aniruddha Sengupta, G. R. Reddy

International Conference on Case Histories in Geotechnical Engineering

This paper presents the results of experimental investigations into the performance of a well-designed layer of sand, and layer of sand mixed with shredded tire (rubber) as low cost base isolators. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The model footing is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the footing and the sand foundation. The whole setup is mounted on the shake table and subjected to sinusoidal motion with varying amplitude and frequency. Acceleration …

Estimating Seismic Settlements From Liquefaction And Cyclic Softening And Their Impact To Design Of A School Building, James Wetenkamp, Jorge Meneses, Zia Zafir

International Conference on Case Histories in Geotechnical Engineering

Estimation of static and seismic settlements is critical for the design of a structure to assess whether the structure can tolerate given levels of total and differential settlements and angular distortion. The design of a public school building required the estimation of both liquefaction-induced settlement due to the presence of a potentially liquefiable layer, and settlement from cyclic softening of soft clay layers. Tolerable levels of differential settlements for the proposed school building were not to exceed 2 inches across the building. The soft clay had a plasticity index of 12, a liquid limit of 32, and SPT blow counts …

Lessons From The Seismic Performance Of Pile-Supported Bridges Affected By Liquefaction During The M8.8 2010 Maule Chile Earthquake, Christian Ledezma

International Conference on Case Histories in Geotechnical Engineering

Ground failure case studies have been the source of the most important advances in geotechnical earthquake engineering over the past 50 years. Documented case histories from the 2010 M8.8 Maule Chile earthquake will, if carefully studied, further advance this field. The 2010 M8.8 earthquake in Chile showed that liquefaction-induced soil-foundation-structure interaction problems are still far from being completely understood. The observed damage and partial collapse of pile-supported bridges like Juan Pablo II, Llacolén, Tubul, La Mochita, and Raqui, is most likely due to the effects of liquefaction-induced lateral and vertical ground displacement, which often causes large ground deformations that impose …

Performance Of Lightweight Structures During Liquefaction From Recent Earthquakes, Jorge F. Meneses, Yun Liao

International Conference on Case Histories in Geotechnical Engineering

Several case histories of lightweight structures performance during liquefaction from recent earthquake are reviewed. The review is focused on performance of lightweight structures in terms of liquefaction-induced vertical settlement, tilting, lateral displacement and their effects on occupancy and functionality of the structures. These case histories were reported during the 1997 M_w 7.4 Caucete- Argentina, 2007 M_w 8.0 Pisco-Peru, 2010 M_w 8.8 Chile, 2010 M_w 7.2 El Mayor-Cucapah, 2010-2011 New Zealand, and 2011 M_w 9.0 Great East Japan earthquakes. The review is performed to identify similarities, discuss conditions, and their effects on foundation and structures. Financial …

Seismic Hazard Assessment And Design Ground Motion: Lessons Learned From Recent Earthquakes, Zhenming Wang

International Conference on Case Histories in Geotechnical Engineering

Recent earthquakes, the 2008 Wenchuan, 2009 L’Aquila, 2010 Haiti, and 2011 Christchurch and Japan in particular, have called attention to the probabilistic seismic hazard maps, particularly the ground motions with 10, 5, and 2 percent probabilities of exceedance in 50 years. As discussed in this paper, these ground motions are artifacts because they were produced from probabilistic seismic hazard analysis (PSHA). PSHA is a mathematical formulation derived from a rigorous probability analysis of the distribution of earthquake magnitudes, locations, and ground-motion attenuation. Some of the assumptions and distributions that PSHA is based on have been found to be invalid in …

Variation Of Intrinsic And Scattering Attenuation Of Seismic Waves With Depth In The Bam Region, East-Central Iran, Majid Mahood

International Conference on Case Histories in Geotechnical Engineering

The attenuation properties of the lithosphere in the Bam region, East-Central Iran, have been investigated. For this purpose, 42 local earthquakes (aftershocks of Bam earthquake, M_w 6.5, 2003) having focal depths less than 25 km have been used. The quality factor of coda waves (Q_c) has been estimated using the single backscattering model. The quality factors Q_p, Q_d (P and direct S-waves) have been estimated using the extended-coda normalization method. Q_i and Q_s (the intrinsic and scattering attenuation parameters) have been estimated for the region. The values of Q_p, Q …

Evaluation Of Site Amplification Of Erbaa, Tokat (Turkey), Muge K. Akin, Steven L. Kramer, Tamer Topal

International Conference on Case Histories in Geotechnical Engineering

The study area, Erbaa, is one of the largest towns of Tokat with a population of 47000 in the northern part of Turkey. Erbaa is in North Anatolian Fault Zone (NAFZ) and partly located on the Kelkit river plain, also referred to as the Erbaa basin. After the disastrous 1942 earthquake (M_s=7.2), the settlement area was seriously damaged and moved farther southwards of its old place in 1944. Dynamic properties of Erbaa soils were determined and shear wave velocity profiles were prepared to be used in site response analyses as part of a microzonation study. During this process, …