Civil and Environmental Engineering Commons^™

A Review Of Current Construction Guidelines To Inform The Design Of Rammed Earth Houses In Seismically Active Zones, David Thompson, Charles Augarde, Juan Pablo Osorio

Articles

Sustainability in the materials we use for construction is a prime concern, focusing on reducing the embodied energy and carbon footprints of the materials used. The cement used in concrete products is responsible for a significant proportion of Man's CO2 emissions and its production requires substantial energy input, as do fired clay products. For this reason, products formed from unfired earthen materials are of increasing interest and the current challenges include devising means of robust design for strength and to address durability concerns. One form of earthen construction that employs an in-situ method is rammed earth, and it is a …

Cyclic Behavior Of Laterally Skewed Special Moment Frame Connections: Experimental Testing And System-Level Analyses, Mohammad Hossein Kashefizadeh

Graduate Theses and Dissertations

Special moment frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs. SMFs provide lateral system stiffness without the use of braces that often obstruct views and architectural features. Current American Institute of Steel Construction (ASIC) provisions (AISC 341-16) provide prequalified SMF connection details; however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF beam-to-column connections. The study presented herein involves system-level dynamic time-history analyses of skewed SMF connections, the analytical component-level investigation into the effect of the concrete slab on behavior of the …

Study Of Fragility Functions For Assessing Damage To Water Pipe Networks Caused By Earthquake Loading, Dylan Joseph Merlo

Master's Theses

The performance of water lifelines during seismic events is an area of ongoing research. In this study we evaluate eight (8) different seismic events and the impact that ground shaking and ground deformations had on water pipeline systems. The overall goal of this work is to provide municipalities and utility providers with tools for mitigating the consequences of seismic hazards on water lifeline systems by analyzing the accuracy of damage estimation models. Three (3) different repair rate models are evaluated using data collected from the seismic events and compared to observed repair rate data. Results are analyzed to examine the …

Durability Of Entrapped Gas In Quasi-Saturated Porous Media: Two Geotechnical Perspectives, Babak Mahmoodichanzab

Electronic Theses and Dissertations

Entrapped gas bubbles in quasi-saturated porous media are of practical importance in the field of science and engineering. Gas bubbles, which may occur naturally or be introduced artificially, significantly influence the mechanical behavior of soil. In this study, the durability of gas is examined from two geotechnical engineering perspectives. In the field of geotechnics, the artificial introduction of gas is being considered, as it has been widely recognized that entrapped gas, even in nearly-saturated sediments, has an appreciable influence on soil’s mechanical behavior. Entrapped gas bubbles in quasi-saturated sediments significantly increase the pore fluid compressibility and suppress the generation of …

Seismic Performance Of Earth Slopes Subjected To Earthquake Mainshock – Aftershock Sequences, Alisha Khanal

Civil Engineering Theses

Mainshocks are usually followed by aftershocks. Aftershocks continue over a period of time with a decreasing frequency and there is not sufficient time for repair and retrofit between a mainshock – aftershock sequence. Typically, aftershocks are smaller in magnitude; however, aftershock ground motion characteristics such as the intensity and duration can be greater than the mainshock due to the changes in the earthquake mechanism and location with respect to the site. The seismic performance of slopes is typically evaluated based on the sliding displacement predicted to occur along a critical sliding surface. Various empirical models are available that predict sliding …

Amplification Of Earthquake Ground Motions In Washington, Dc, And Implications For Hazard Assessments In Central And Eastern North America, Thomas L. Pratt, J. Wright Horton Jr., Jessica Munoz, Susan E. Hough, Martin C. Chapman, C. Guney Olgun

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The extent of damage in Washington, DC, from the 2011 M_W 5.8 Mineral, VA, earthquake was surprising for an epicenter 130 km away; U.S. Geological Survey “Did-You-Feel-It” reports suggest that Atlantic Coastal Plain and other unconsolidated sediments amplified ground motions in the city. We measure this amplification relative to bedrock sites using earthquake signals recorded on a temporary seismometer array. The spectral ratios show strong amplification in the 0.7 to 4 Hz frequency range for sites on sediments. This range overlaps with resonant frequencies of buildings in the city as inferred from their heights, suggesting amplification at frequencies to …

Scale Model Shake Table Testing Of Shallow Embedded Foundations In Soft Clay, Steven Kuo

Master's Theses

This research involves shake table testing of 1g scale models that mimic the coupled seismic response of a structure on a shallow mat foundation and foundation soil (known as soil-foundation-structural-interaction or SFSI). In previous research, SFSI effects have been quantified through analytical models, numerical analyses, and limited field data. This research works towards increasing the amount of empirical data through scale model shake table testing. A suite of earthquake time histories is considered in evaluating a nominal 10^th scale soil-structure model using a flexible wall barrel on a 1-D shake table. San Francisco Young Bay Mud (YBM) is used …

Seismic Microzonation Of Great Toronto Area And Influence Of Building Resonances On Measured Soil Responses, Dimitar Genchev Mihaylov

Electronic Thesis and Dissertation Repository

A pilot seismic microzonation of the Greater Toronto Area (GTA) is used to establish the conditions and limitations of geophysical methods for site response investigations in city conditions. Maps of fundamental soil resonant frequencies, amplifications at these frequencies and interpolated average shear wave velocity of top 30 m of soil profile (VS- 30) used in soil classification were compared to the maps of drift thickness and surficial geology for the GTA. The non-applicability of the interpolated VS-30 map for site classification between measured test points is indicated. It is also shown that the soil response cannot be estimated properly using …

Probabilistic Fault Displacement Hazard Analysis For Reverse Faults And Surface Rupture Scale Invariance, Zachary E. Ross

Master's Theses

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Times New Roman'}

A methodology is presented for evaluating the potential surface fault displacement on reverse faults in a probabilistic manner. This methodology follows the procedures put forth for Probabilistic Fault Displacement Hazard Analysis (PFDHA). Empirical probability distributions that are central to performing a PFDHA are derived from field investigations of reverse faulting events. Statistical analyses are used to test previously assumed properties of scale invariance with respect to magnitude for normalized displacement. It is found that normalized displacement is statistically invariant with respect to magnitude and focal mechanism, allowing for the …

Scale Model Shake Table Testing Of Underground Structures In Soft Clay, Victor A. Crosariol

Master's Theses

Underground structures perform an important role in transportation systems in many seismically active regions around the world, but empirical data regarding the seismic behavior of these structures is limited. This research works towards filling that empirical gap through the use of scale model shake table testing. Underground seismic soil-structure interaction (USSSI) effects were investigated for a stiff rectangular tunnel cross-section embedded within soft clay. San Francisco Young Bay Mud was used as a prototype soil for developing a scale model soil mixture consisting of kaolinite, bentonite, class C fly ash, and water. A single cell Bay Area Rapid Transit (BART) …

Backend Framework And Software Approach To Compute Earthquake Parameters From Signals Recorded By Seismic Instrumentation System, Raman Attri

Raman K. Attri

Computation of seismic parameters and its interpretation from the recorded earthquake signal is empowered by digital data acquisition systems. This enables seismologist to automatically compute all the relevant parameters. Futuristic applications require extensive software development to implement seismic prediction and forecasting models. While developing such models, software developer prefer to write their own in-house analysis & modeling software with complete control over the required computations and models. This paper presents simplified mathematical framework of the seismic events and back-end computational software logic & algorithm to provide a simple framework to software engineers develop customized seismic analysis & computation software.

Displacement Of Bridge Abutment Under Earthquake Loading, Yulman Munaf, Shamsher Prakash

International Conference on Case Histories in Geotechnical Engineering

Bridge abutments may experience significant displacements during earthquakes. A two-dimensional model has been developed considering sliding and overturning displacement and 1) strain dependent soil stiffness and soil damping and 2) horizontal and vertical time dependent seismic load. The displacements are computed from the static equilibrium position where the seismic backfill force increments are considered for determining the active earth force acting behind the abutment wall. This means that the permanent displacement increment occurred if the acceleration acts towards the backfill and the abutment wall moves away from the backfill. The total displacement at the top of bridge abutment is calculated …

Software For Seismic And Vibration Analysis, Raman K. Attri

Raman K. Attri

No abstract provided.

A Simplified Overview: How The Earthquake Parameters Are Computed From Recorded Seismic Signals?, Raman Attri

Raman K. Attri

The earthquake phenomenon is one of the unpredictable and complex geo-logical phenomenon happening under the earth surface. The recording and its interpretation of recorded earthquake signal have always been a prime concern of the seismologists. This paper discusses in a very simplified manner how these complex parameters are computed.

Pile Response Characteristics Of Liquefied Soil Layers In Shaking Table Tests Of A Large Scale Laminar Shear Box, Kaeko Yahata, Yasutsugu Suzuki, Hideki Funahara, Mutsuhiro Yoshizawa, Shuji Tamura, Kohji Tokimatsu

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

To better understand the causes of pile damages during earthquakes such as Hyogoken-Nanbu Earthquake, shaking table tests of soil-pile-structure interaction models were done using a large scale laminar shear box. Because the pile response is affected by both the ground motion and the structure's inertial forces, three models were test & a soil-pile model and two soil-pile-structure models. For the latter models, superstructures with long and short natural periods were tested separately. Through comparisons among the three cases, the influences on the pile response due to the inertial force of the superstructure for the long and short natural periods were …