Engineering Commons^™

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 …

Kinematic Demands On Pile-Supported Wharves Due To Liquefaction-Induced Lateral Ground Deformations, Thomas John Torkelson Ii

Dissertations and Theses

Kinematic demands from lateral soil deformations can be a major cause of damage to maritime and highway transportation structures such as wharves, ports, and bridges. Data from five centrifuge tests on pile-supported wharves were used to evaluate the accuracy of Newmark Sliding Block Analysis in estimating the kinematic demands on piles. The piles in the centrifuge tests were subjected to varying degrees of liquefaction-induced lateral ground deformations. Pile-pinning effects were included in the analysis by incorporating the lateral pile resistance in the limit-equilibrium slope stability analysis. The results of the analysis have shown that the median Newmark displacements better estimated …

Development Of A Design Guideline For Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading, Milad Souri

Dissertations and Theses

Extensive loss of stiffness and strength in liquefied soils can cause large ground deformations during strong earthquake shaking. One of the major sources of damage in pile foundations in liquefied soil is the excessive deformation due to lateral spreading. Pile-supported wharves subjected to earthquake motions are expected to accommodate inertial loads imposed at pile head from the superstructure as well as the kinematic loads imposed on piles from the lateral ground deformations. Current design codes significantly vary on how to combine inertia and kinematic demands. Recent research on soil-foundation-structure interaction suffers from lack of experiment-based data. There is a serious …

Behavior Of Non-Ductile Slender Reinforced Concrete Columns Retrofit By Cfrp Under Cyclic Loading, Wisam Amer Aules

Dissertations and Theses

In the Middle East region and many countries in the world, older reinforced concrete (RC) columns are deemed to be weak in seismic resistance because of their low amount of reinforcement, low grades of concrete, and large spacing between the transverse reinforcement. The capacity of older RC columns that are also slender is further reduced due to the secondary moments. Appropriate retrofit techniques can improve the capacity and behavior of concrete members. In this study, externally bonded Carbon Fiber Reinforced Polymer (CFRP) retrofit technique was implemented to improve the behavior of RC columns tested under constant axial load and cyclic …

Development Of A Design Guideline For Bridge Pile Foundations Subjected To Liquefaction Induced Lateral Spreading, Jonathan A. Nasr

Dissertations and Theses

Effective-stress nonlinear dynamic analyses (NDA) were performed for piles in liquefiable sloped ground to assess how inertia and liquefaction-induced lateral spreading combine in long-duration vs. short-duration earthquakes. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of earthquake durations. The NDA results were used to evaluate the accuracy of the equivalent static analysis (ESA) recommended by Caltrans/ODOT for estimating pile demands. Finally, the NDA results were used to develop new ESA methods to combine inertial and lateral spreading loads for estimating elastic and inelastic pile demands.

The NDA results showed that pile …