Civil and Environmental Engineering Commons^™

Performance Of Helical Piles Retrofitted With A Novel Collar Vane Under Lateral And Torsional Loads, Juan Sebastian Carvajal Munoz

Electronic Theses and Dissertations

Helical piles are lightweight deep foundations designed to support both compressive and uplift loads by mobilizing the shear strength of soil adjacent to helical plates that are welded to an extendable shaft. Helical piles are relatively inexpensive, can be installed quickly utilizing non-specialized equipment, and they are suitable for a wide range of soil conditions. However, helical piles are precluded from many applications due to their inability to support substantial lateral and torsional loads. To overcome this limitation, a novel easy-to-install Collar Vane is implemented to augment the lateral and torsional capacity of helical piles.

The Collar Vane consists of …

Cyclic Behavior Of Transitional Fine-Grained Soils In Northern Willamette Valley, Frank Jarman

Civil and Environmental Engineering Master's Project Reports

As discussed within studies from Idriss and Boulanger (2008) and Bray and Sancio (2006), the undrained cyclic shear behavior of low-plasticity fine-grained soils will transition between liquefaction (sand-like behavior) to cyclic softening (clay-like behavior) over a narrow range of plasticity index (PI). Despite not being sufficiently understood, the cyclic behavior of low plasticity silts has become an increasingly important field of study due to the significant impact it has on ground deformations and infrastructure failure in areas that are seismically active. Laboratory tests were performed on soils by third party consultants on a site located in the northern Willamette Valley, …

Liquefaction Triggering In Low-Plasticity Silts And Effects Of Liquefaction-Induced Lateral Spreading On A Reinforced-Concrete Pile, Jared A. Martinez

Civil and Environmental Engineering Master's Project Reports

Liquefaction triggering and post-liquefaction effects on lateral loading of deep foundations is an emerging area of study. This project presents: the results of cyclic direct simple shear (CDSS) testing on a low-plasticity alluvial silt collected in Portland, Oregon; and analysis of the combined effects of liquefaction-induced lateral spreading on a reinforced-concrete pile using data collected from a shake table test. The former research determines the liquefaction susceptibility and post-liquefaction characteristics of a local transitional soil using stress-controlled CDSS testing, the latter explores the complex lateral loading a reinforced-concrete pile undergoes during seismic loading with liquefaction-induced lateral spreading of the ground …

Undrained Cyclic Loading Of Low Plasticity Silty Soils In The Pacific Northwest Using Laboratory And Field Cyclic Shear Testing, Angelica Melissa Preciado Reyes

Dissertations and Theses

The cyclic behavior of a fine-grained low plasticity silty soil (plasticity index of approximately 15) at a site in Portland, Oregon, is characterized using a field and laboratory cyclic shear test program. The field cyclic tests were performed using the NHERI@UTexas large mobile shakers T-Rex and Rattler. The laboratory tests were performed using resonant column torsional shear and cyclic direct simple shear devices. This testing program's results were used to evaluate the soil's potential to develop excess pore water pressure with cyclic shear strains ranging from 0.00001% to 3%. The laboratory cyclic test results are compared against field cyclic test …

Multi-Index Prediction Method For Maximum Convergence Deformation Of Underground Powerhouse Side Wall Based On Statistical Analysis, Shun-Tian Luo, Fan-Jie Yang, Hui Zhou, Chuan-Qing Zhang, Xu-Hong Wang, Tao L, Yong Zhu, Jing-Jing Lu

Rock and Soil Mechanics

Accurate prediction of surrounding rock deformation is one of the important prerequisites for scientific design and safe construction of large underground caverns. Existing prediction methods for surrounding rock deformation of underground cavern are mainly based on the monitoring data of the constructed locations surrounding rock deformation to predict the deformation trend of unconstructed locations. This causes difficulties in meeting the requirement of accurately predicting the total surrounding rock deformation of in engineering survey and design stage. Based on the statistical analysis of measured data from 31 large underground caverns in China, a method for predicting the maximum convergence deformation of …

Numerical Simulation Of Continuous Cone Penetration And Interpretation Of Cptu Dissipation Tests, Andrew Phillip Eugene Huffman

Dissertations and Theses

The piezocone penetration test (CPTu) is a commonly used method of geotechnical site investigation. The CPTu is especially useful because it provides a nearly continuous data profile of in-situ soil behavior, which can be correlated to useful engineering parameters. However, limitations exist for interpretation of geotechnical properties from CPTu data and for numerical analysis of cone penetration problems. The research presented in this thesis examines interpretation of coefficient of consolidation from CPTu dissipation test data and implementation of an algorithm to advance numerical simulation of cone penetration problems. This thesis presents analysis of CPTu dissipation responses from field-measured and numerically …

Dynamic Response Of Pile Foundation Under Pile-Soil-Fault Coupling Effect In Meizoseismal Area, Jing-Bin He, Zhong-Ju Feng, Yun-Xiu Dong, Hai-Bo Hu, Chuang Liu, Sui-Zhu Guo, Cong Zhang, Min Wu, Zhen Wang

Rock and Soil Mechanics

In order to study the dynamic response characteristics of pile foundation under the pile-soil-fault coupling effect, four different types of seismic waves with the peak acceleration of 0.35g are selected for shaking table test. The acceleration response, relative displacement of pile top, bending moment of pile body and damage of pile foundation under different types of seismic waves are studied. The test results show that the parameters of the pile in hanging wall are obviously larger than those in the footwall of the fault, showing the hanging wall effect. The peak acceleration of pile top is greater than that of …

Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt

Dissertations and Theses

Strong earthquake shaking is a natural hazard threat in the Pacific Northwest. Soil failure due to strong earthquake shaking -- known as cyclic soil failure or liquefaction -- is expected to cause large ground deformations and damage to roads, bridges, and other civil infrastructure. Cyclic soil strength (CRR) is often characterized with in-situ geotechnical tests including the cone penetration test (CPT). Relationships between CRR and in-situ test data are not well established for soils in the Pacific Northwest. Portland State University, in partnership with New Albion Geotechnical has compiled a database of cyclic lab tests for Pacific Northwest soils to …

Analysis Of The Evolution Of Excess Pore Water Pressure In Soft Soil Under Linear Unloading, Xu-Chao Shi, Yun-De Sun

Rock and Soil Mechanics

At present, the research on the consolidation deformation of soft soil under unloading mainly focuses on the instantaneous unloading. In order to clarify the evolution of consolidation deformation of soft soil under linear unloading, through the one-dimensional consolidation theory of Terzaghi and the principle of effective stress, an effective method is proposed to study the general solution of the soft soil foundation under the arbitrary unloading rate and solve the analytical solution of the consolidation equation under linear unloading. The results show that: (1) the negative excess pore pressure generated in soft soil foundation under linear unloading can be divided …

Undrained Cyclic Shear Resistance Of Low Plastic Silts, Rawan Almoumen

Dissertations and Theses

A magnitude 9 Cascadia Subduction Zone earthquake is expected to trigger widespread liquefaction in loose material in Oregon. The geotechnical engineering studies have determined that the Willamette Silts may be susceptible to liquefaction or cyclic softening, as their plasticity indices ranges between non-plastic to low plasticity. While the majority of past studies have focused on liquefaction of sand and cyclic behavior of clays, there is not enough data on the cyclic response behavior of silty soils and the liquefaction susceptibility of these soils. A research focus in the geotechnical engineering program at Portland State University revolves around is performing cyclic …

Incorporating Geophysical Data In Slope Stability Modeling For Two Slopes In Arkansas, Vanessa Lebow

Graduate Theses and Dissertations

Slope failures in the United States alone cause millions of dollars in damage to infrastructure, threaten national monuments, create environmental hazards, and take an average of 25-50 lives a year. With the inevitable construction that occurs on slopes, it is imperative that the slopes be properly designed which requires a thorough understanding of slope grade, subsurface soil conditions, soil strength parameters, water table locations, and depth to bedrock across the entire site. The preferred method of data collection would be to use borings and other in-situ methods; however, sometimes due to cost constraints or site accessibility only a very limited …

A Unified Risk-Based Framework For Assessing Sustainability And Resiliency Of Civil Infrastructure, Thomas Adam Robbins

Boise State University Theses and Dissertations

As of February 2019, the National Aeronautics and Space Administration (NASA) has reported since 1880 the average global temperature has increased 1°C, with the warmest year on record being 2016. As the years continue to pass, it is becoming more evident that climate change is occurring, which is known to be a catalyst for climatic weather events. Statistically speaking, these events are more prevalent, and catastrophic exemplified as hurricanes, earthquakes, flooding, and fires. In addition to the increase of potentially catastrophic events, society as a whole has become more conscientious in the use and preservation of natural resources, waste generation, …

Discussion: Effect Of Bentonite Slurry Pressure On Interface Friction Of Pipe Jacking, Ciaran Reilly, Trevor Orr

Articles

Pipe jacking is a technique used to construct tunnels by pushing prefabricated pipes through the ground from an entrance shaft to an exit shaft. This technique is referred as microtunneling in U.S. terminology, therefore, in the rest of the text, pipejacking and microtunneling will be used as having the same meaning. Pipe jacking is a more economical alternative to segmental lined tunnels. However, the main limitation of pipe jacking is the jacking distance, which is directly dependent on the friction between the pipe and the soil. Therefore, reducing the friction between the pipe and soil is a critical issue in …

Stabilization Of Dredged Materials In Ohio: An Investigation Of Mechanical, Chemical And Biological Dewatering Techniques, Erika Howard

Williams Honors College, Honors Research Projects

Each year, materials are excavated from oceans and lakes in order to keep the waterways open so that ships can safely pass through. These excavated, or dredged, materials are then discarded, usually being returned to the body of water from which they were removed. Beginning in 2020, the Ohio Environmental Protection Agency (OEPA) will no longer allow this to occur. Therefore, the purpose of this project is to investigate beneficial uses for dredged materials in Lake Erie, and to address the best management practices for dewatering these materials, as set forth in the Lake Erie Protection and Restoration Plan created …

Geosynthetic Reinforcement For Unpaved Roads – Recent Experience, Ciaran Reilly, Keith Nell

Conference papers

Modern geosynthetic materials, including geotextiles and geogrids, are often used to generate savings in materials and time on construction projects. Geosynthetics are used as reinforcement and separation membranes for unpaved roads that are supported by low strength or unsuitable subgrades. When geosynthetics are used, unsuitable subgrades can be left in place and reduced thicknesses of road base are required. This paper reviews the design methods currently used to build geosynthetic reinforced unpaved roads and documents the validation of these design approaches. A number of recent case histories of projects in the UK and Ireland are outlined, showing the use of …

Resistivity Profiles Of Perth Soil In Australia In Leak-Detection Test, Lopa M. Pandey, Sanjay K. Shukla, Daryoush Habibi

Research outputs 2014 to 2021

The use of a suitable leak-detection system for the prevention and mitigation of pollution due to lining system failures is integral to the proper management of landfill facilities. This paper briefly summarises various methods of leak detection that are currently being practised. The details of a newly developed leak-detection technique are also presented. The tests were conducted to evaluate the performance of the new technique by use of controlled leakage. The resulting resistivity profiles for Perth soil in Australia were obtained at 10 min. This method is found to be effective in detecting and locating liner leakage issues within 30 …

Commercialization Of A Small, Lightweight, Low-Cost Seismic Borehole Receiver, Rachel Adams

Theses and Dissertations--Civil Engineering

Herein, conceptualization of a recently patented seismic borehole receiver and its components is developed for commercialization. The device is significantly cheaper, lighter, and smaller than existing technologies on the market. Additionally, it has the potential to achieve better seismic readings than its competitors via patented sensor-to-borehole coupling mechanism. It is the hope that the commercialization of this device will not only provide a more affordable alternative to engineers and geophysicists in the existing market, but the significant cost difference may open new seismic measurement opportunities in the developing world. Its compact size and light weight will increase mobility, allowing investigators …

Detecting Anomalous Inclusions In Soil Profiles: Encouraging The Use Of Geophysics To Solve Engineering Problems, Barbara Luke, Carlos Calderon-Macias

Civil and Environmental Engineering and Construction Faculty Research

Geotechnical site investigations often do not take full advantage of geophysical methods. As examples, when delineating cemented strata and when detecting shallow cavities, investigations can be enhanced greatly for low additional cost by incorporating seismic surface-based measurements.