Engineering Commons^™

Dynamic Field Test Of A Model Levee Founded On Peaty Organic Soil Using An Eccentric Mass Shaker, E. T. Reinert, S. J. Brandenberg, J. P. Stewart, R. E.S. Moss

Civil and Environmental Engineering

A dynamic field test of a model levee was performed to study the behavior of very soft and compressible peaty organic soils that commonly underlie levees in the Sacramento / San Joaquin Delta in northern California. This first-of-its-kind test applied dynamic loads to the levee/peat system using a large eccentric mass shaker mounted on the levee crest. Loads from the shaker and the inertia of the levee section are transmitted to the peaty organic soils as base shear stresses, and rotational demands that manifest as normal pressures at the embankment/peat interface. We seek to characterize the transmission of seismic energy …

Dynamic Field Test Of A Model Levee Founded On Peaty Organic Soil Using An Eccentric Mass Shaker, E. T. Reinert, S. J. Brandenberg, J. P. Stewart, R. E.S. Moss

Civil and Environmental Engineering

A dynamic field test of a model levee was performed to study the behavior of very soft and compressible peaty organic soils that commonly underlie levees in the Sacramento / San Joaquin Delta in northern California. This first-of-its-kind test applied dynamic loads to the levee/peat system using a large eccentric mass shaker mounted on the levee crest. Loads from the shaker and the inertia of the levee section are transmitted to the peaty organic soils as base shear stresses, and rotational demands that manifest as normal pressures at the embankment/peat interface. We seek to characterize the transmission of seismic energy …

Model Performance Sensitivity To Objective Function During Automated Calibrations, Misgana Muleta

Civil and Environmental Engineering

Previous studies have reported limitations of the efficiency criteria commonly used in hydrology to describe goodness of model simulations. This study examined sensitivity of model performance to the objective function used during automated calibrations. Nine widely used efficiency criteria were evaluated for their effectiveness as objective function, and goodness of the model predictions were examined using 13 criteria. Two cases (Case I: Using observed streamflow data and Case II: Using simulated streamflow) were considered to accomplish objectives of the study using a widely used watershed model (SWAT) and good-quality field data from a well-monitored experimental watershed. Major findings of the …

Coseismic Tectonic Surface Deformation During The 2010 Maule, Chile, MW 8.8 Earthquake, Keith Kelson, Robert C. Witter, Andrés Tassara, Isabelle Ryder, Christian Ledezma, Robb Moss, Laurie Johnson

Civil and Environmental Engineering

Tectonic deformation from the 2010 Maule (Chile) M_w 8.8 earthquake included both uplift and subsidence along about 470 km of the central Chilean coast. In the south, deformation included as much as 3 m of uplift of the Arauco Peninsula, which produced emergent marine platforms and affected harbor infrastructure. In the central part of the deformation zone, north of Constitución, coastal subsidence drowned supratidal floodplains and caused extensive shoreline modification. In the north, coastal areas experienced either slight uplift or no detected change in land level. Also, river-channel deposition and decreased gradients suggest tectonic subsidence may have occurred in …

A Formal Bayesian Approach For Uncertainty Analysis Of A Watershed Model, Misgana K. Muleta

Civil and Environmental Engineering

Uncertainty analysis (UA) has received substantial attention in water resources during the last decade. Bayesian approaches are often preferred for UA. This study describes a formal Bayesian approach for the assessment of parameter uncertainty and predictive uncertainty using a spatially distributed hydrologic model and will demonstrate its application using data from a well monitored experimental watershed. A Markov-Chain Monte Carlo (MCMC) scheme has been used to sample posterior parameter distributions. A formal, flexible likelihood function that explicitly accounts for heteroscedasticity, temporal correlation and non-normality of simulation residuals has been used to describe closeness of the simulated and observed streamflow. Performance …

Approaches To Control Nitrate Pollution In The San Joaquin Watershed, Misgana K. Muleta, Stephen Clayton

Civil and Environmental Engineering

No abstract provided.

Evaluating Alternative Hydraulic Solutions To Limit Nutrient Contamination Of An Aquifer In Southern California, Jake M. Perry, Misgana K. Muleta

Civil and Environmental Engineering

Many small communities depend on groundwater sources for drinking water and they often use septic tanks for wastewater treatment and disposal. Nitrate and other pollutants leaking from poorly designed septic tank systems can percolate to the aquifers and alter quality of the groundwater. This study describes a groundwater model developed using Visual MODFLOW for an aquifer that is used as a water supply source for the communities of Beaumont and Cherry Valley, CA. The aquifer has been contaminated by nitrates leaking from septic tank systems. The model will assist in clarifying the extent of interactions between nitrate pollutants, percolation from …

Uncertainty Analysis And Calibration Of Swmm Using A Formal, Bayesian Methodology, Misgana K. Muleta

Civil and Environmental Engineering

Importance of uncertainty analysis (UA) to estimate the degree of reliability associated with model predictions is being understood. Consequently, literature that describes various Bayesian methods for the assessment of parameter and model predictive uncertainty has been steadily rising. Applications dealing with urban stormwater management are, however, very limited. This study demonstrates successful application of a formal Bayesian methodology for UA of the U.S. EPA Stormwater Management Model (SWMM), a widely used urban stormwater management model, and illustrates the methodology using a highly urbanized watershed in southern California. DREAM(ZS), a recently developed effective and efficient sampling algorithm, and a generalized, formal …

Discussion Of “Comparison Of Base Shears Estimated From Floor Accelerations And Column Shears”, Rakesh K. Goel

Civil and Environmental Engineering

In lieu of a provided abstract, the first paragraph is provided:

The author agrees with Dr. Pinho about difficulties associated with the use of different damping models in nonlinear dynamic analysis. However, the focus of the original manuscript was to illustrate the difference between base shear estimated from floor accelerations, denoted as inertial base shear, and base shear estimated from column shears, denoted as the structural base shear. The difference between the two base shears exists regardless of the damping model used in the nonlinear analysis. In order to illustrate this conclusion, the Los Angeles building of the original manuscript …

Scale Model Shake Table Testing Of Seismic Earth Pressures In Soft Clay, Robb Moss, R.E. Noche

Civil and Environmental Engineering

There is much uncertainty in seismic earth pressures for basement wall design and retaining wall design in clay soil. The research presented herein uses a scale model testing platform on a 1g shake table to measure the distribution and magnitude of seismic earth pressures for the prototype soil conditions of San Francisco Young Bay Mud (YBM). Similitude scaling of the dynamic soil properties, the wall dimensions, and the input time histories (among other variables) affords accurate modeling of the prototype scale wall. For basement conditions, inertial soil structure interaction (SSI) effects are included in the experiments. Care is taken to …

Improving Model Performance Using Season-Based Evaluation, Misgana Muleta

Civil and Environmental Engineering

Computer models have become vital decision-making tools in many areas of science and engineering including water resources. However, models should be properly evaluated before use to improve the likelihood of making sound decisions based on their results. The model evaluation technique practiced today in hydrology assumes that model parameters are season insensitive and attempts to identify “optimal” values that would describe watershed behavior during dry and wet seasons. This assumption could compromise accuracy of model predictions. This study demonstrates performance improvement that would be achieved when a season-based model evaluation approach is pursued. A global sensitivity analysis (SA) model has …

Use Of Post-Consumer Corrugated Fiberboard As Fine Aggregate Replacement In Controlled Low-Strength Materials, James L. Hanson, Gregory M. Stone, Nazli Yesiller

Civil and Environmental Engineering

This study was conducted to investigate the use of post-con­sumer corrugated board in controlled low-strength material (CLSM) applica­tions. Corrugated fiberboard (termed corrugate), which constitutes a significant fraction of the municipal solid waste stream in the United States (approximately one third by weight), was used as a partial replacement for fine aggregate in CLSM at aggregate replacement ratios ranging from 0 % (i.e., control) to 6 %. The corrugate was fiberized (i.e., repulped) in a blender prior to being mixed with other constituents in the CLSM. The density, air con­tent, and flow consistency of the fresh CLSM were determined, and bleeding …

Quality Of Traffic Flow On Urban Arterial Streets And Its Relationship With Safety, Vinayak V. Dixit, Anurag Pande, Mohamed Abdel-Aty, Abhishek Das, Essam Radwan

Civil and Environmental Engineering

The two-fluid model for vehicular traffic flow explains the traffic on arterials as a mix of stopped and running vehicles. It describes the relationship between the vehicles’ running speed and the fraction of running vehicles. The two parameters of the model essentially represent ‘free flow’ travel time and level of interaction among vehicles, and may be used to evaluate urban roadway networks and urban corridors with partially limited access. These parameters are influenced by not only the roadway characteristics but also by behavioral aspects of driver population, e.g., aggressiveness. Two-fluid models are estimated for eight arterial corridors in Orlando, FL …

Decisive Disaster Debris Management, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.

Bounding The Probability Of Failure For Levee Systems, Justin C. Hollenback, Robb E.S. Moss

Civil and Environmental Engineering

An exact solution for the probability of failure of large complex infrastructure systems is rarely obtainable; however the probability of failure can often be bounded. An example of this type of system is the levee system in the California Bay Delta. Large levee systems often consist of many components arranged in series and parallel sub‐systems. There is the problem of defining component (or reach) length, and therefore the total number of components in the system where component length is dependent on failure mode. Methods of bounding probability of failure based on uni‐, bi‐, and tri‐modal component probability of failure are …

Teaching Reliability At The Undergraduate Level, Robb E.S. Moss

Civil and Environmental Engineering

For Cal Poly's Civil and Environmental Engineering curriculum a stand‐alone introductory course called Engineering Risk Analysis introduces concepts of reliability analysis. This course encompasses all the sub‐disciplines in civil and environmental engineering. After five years of teaching this course there are a number of lessons that may be useful to other instructors including; solving a simple example problem using multiple methods, focusing on the normal and lognormal distributions for a quick preliminary solution, using reliability spreadsheet solutions, and allowing the students to develop their own applications of probabilistic tools. A discussion of the course format, references and resources, pedagogy devices, …

Linking Cyclic Stress And Cyclic Strain Based Methods For Assessment Of Cyclic Liquefaction Triggering In Sands, J. A. Schneider, R. E.S. Moss

Civil and Environmental Engineering

Contradictory conclusions may arise when assessing liquefaction resistance of sands based on penetrat1on tests and shear wave velocity. To provide a more unified analysis framework, th1s letter couples cyclic stress and cyclic strain based analysis of liquefaction triggering using site-specific correlations between penetration resistance and small strain shear modulus from shear wave velocity using the seismic cone tests. Cyclic strain theory provides a robust lower limit to liquefaction resistance, and analyses indicate that relatively high ratios of small strain stiffness to penetration resistance lead to high liquefaction resistance at relatively low cyclic stress ratios_ The increased resistance to liquefaction from …

Modeling Erosion And Sedimentation Processes In The Chorro Creek Subwatershed To Evaluate And Develop Effective Watershed Management Approaches, Michael Randall, Misgana K. Muleta

Civil and Environmental Engineering

The Morro Bay Watershed, located in San Luis Obispo County, California, covers more than 48,000 acres of land and discharges into Morro Bay through the Morro Bay National Estuary (MBNE). The Chorro Creek Subwatershed consists of approximately 30,000 acres of the overall watershed. The MBNE provides an ecosystem that supports a variety of wildlife, from the common sea gull to the endangered sea otter. The estuary is also home to over 200 species of birds. The operational waterfront of the Morro Bay Harbor was and continues to be a strong supporter to the local economy of the City of Morro …

Improving Model Performance Using Dynamic Evaluation And Proper Objective Function, Misgana K. Muleta

Civil and Environmental Engineering

Models have become important decision making aids. Model evaluation (i.e., global sensitivity analysis, calibration and uncertainty analysis), is crucial to improve their prediction accuracy and reduce the likelihood of making decisions that could lead to undesirable policy outcomes. The conventional approach assumes that model parameters are insensitive to season irrespective of the temporal variability of input forcings such as rainfall. This assumption could significantly compromise model performance for low flow seasons and/or high flow seasons depending on the calibration method pursued. This study will demonstrate the advantage of dynamic (seasonal) model evaluation in improving performance compared to the traditional approach. …

Assessment Of Public Perception Of User-Based Fees And Tolls To Finance Transportation Infrastructure Improvements, Anurag Pande, Cornelius Nuworsoo, Adrianna Jordan, Reuben Juster, Carmeron Hunter Shew, Joe Yu

Civil and Environmental Engineering

With aging infrastructure and declining purchasing power of tax receipts new mechanisms of financing transportation alternatives are gaining increasing interest. Fuel taxes are and have been for some time the primary source of transportation finance in United States. Fuel taxes are fixed amounts that rarely change and which lose purchasing power over time as prices escalate. In addition, improvements in fuel economy can further erode the revenue stream from the gas tax. This study explores the public’s attitude about user based fees collected through tolls that are directed at specific infrastructure projects using the Inland Empire region of California as …

Retesting Of Liquefaction/Nonliquefaction Case Histories From The 1976 Tangshan Earthquake, R. E.S. Moss, R. E. Kayen, L-Y Tong, S-Y Liu, G-J Cai, J. Wu

Civil and Environmental Engineering

A field investigation was carried out to retest liquefaction and nonliquefaction sites from the 1976 Tangshan Earthquake in China. These sites were carefully investigated in 1978/1979 using standard penetration test (SPT) and cone penetration test (CPT) equipment, however the CPT measurements are obsolete because of the now nonstandard cone that was used at the time. In 2007 a modern cone was mobilized to retest 18 select sites that are particularly valuable because; of the intense ground shaking, high fines content, and/or the site did. Of the sites reinvestigated and carefully processed, 13 are considered accurate representative case histories. Two of …

Assessment Of State Composting Regulations In The United States, Nazli Yesiller, Samuel A. Vigil, James L. Hanson

Civil and Environmental Engineering

This investigation was conducted to identify the current "status of state composting regulations in the U.S. using an extensive survey administered to regulators from all 50 states. Questions were included regarding: background information on composting: status of regulations: regulatory details including feedstock specific provisions and regulatory framework with respect to MSW regulations: details regarding type, properties, and amount of materials handled by composting activities; outgoing materials and storage of materials; type of composting facilities: initial development of the regulations; level of rigor of regulations: enforcement and reporting requirements; efficiency and level of satisfaction with regulations: permitting fees; and modifications to …

Shake Table Testing Of Seismic Soil-Foundation-Structure-Interaction, Robb E.S. Moss, Steven Kuo, Victor Crosariol

Civil and Environmental Engineering

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 the foundation soil (termed soil‐foundation‐structure‐interaction or SFSI). In previous research, SFSI effects have been quantified through analytical models, numerical analyses, and limited field data. This research is working towards increasing the amount of empirical data through scale model shake table testing. A suite of earthquake times histories are considered in evaluating a 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 Response Of Peaty Organic Soils As A Levee Foundation Material, Robb E.S. Moss, Justin C. Hollenback

Civil and Environmental Engineering

The dynamic response of peaty organic soils is not well understood but its poor competency as an engineering material is well known. Its use as a foundation material is generally avoided through careful selection of project location, or removal and replacement with more suitable material. In certain situations peaty organic soils are unavoidable because of prior land use and subsequent development of infrastructure. In a delta environment levees are often found to be overlying peaty organic deposits, the California Bay Delta and New Orleans levee systems are two important examples. The Bay Delta is in a seismically active area and …

Traffic Engineering In A Hybrid Format: More Learning With Less Meeting, Anurag Pande, Joe Grimes

Civil and Environmental Engineering

In the Civil Engineering curriculum at Cal Poly, CE 421 (Traffic Engineering) course is intended to provide students with details of driver behavior, traffic characteristics, and design considerations for addressing traffic problems. In fall 2008, this class was taught in traditional Face-to-Face (f2f) lecture format. Based on the student feedback received at the end of the quarter and success in achieving learning outcomes, it was determined that the course should be more student-centered and there should be a 2-way feedback mechanism between students and instructor throughout the quarter. Based on this evaluation, the course was redesigned and taught in the …

Real-Time Crash Risk Estimation: Are All Freeways Created Equal?, Anurag Pande, Abhishek Das, Mohamed A. Abdel-Aty, Hany Hassan

Civil and Environmental Engineering

Underground loop detectors have been recently used by many researchers to investigate the links with real-time crash risk and the traffic data. An issue that has been raised but not explicitly addressed in these studies is how the results from one freeway might transfer to another. This study attempts to look at the relationship between crash risk and real-time traffic variables from a freeway corridor (I4 eastbound in Orlando, FL) and attempts to apply the models to three other freeway corridors (I-4 westbound, and I-95 north and southbound). Traffic data used in the study were collected using loop as well …

Effects Of Liquefaction-Induced Ground Failure On Bridges, Roads, Railroads And Lifeline Systems, Christian Ledezma, Scott Ashford, Tara Hutchinson, Robb E.S. Moss, Pedro Arduino, Robert Kayen, Scott Olson

Civil and Environmental Engineering

No abstract provided.

Landfill Temperatures Under Variable Decomposition Conditions, Nazli Yesiller, James L. Hanson, H. Yoshida

Civil and Environmental Engineering

This study was conducted to evaluate temperature, gas, and leachate data at two landfills in similar climatic regions (Detroit, Michigan, USA and Asahikawa, Hokkaido, Japan) to determine the interrelations between heat production and resulting waste temperatures and gas and leachate levels in landfills under variable decomposition conditions. Significant temperature increases occurred under long-term anaerobic conditions. Stable elevated temperatures under anaerobic conditions were observed for wastes at central locations. Seasonal fluctuations in both temperature and gas existed at shallow depths and near perimeter locations. Placement of an overfill of fresh wastes over old wastes affected temperatures, yet did not significantly influence …

Comparison Of Base Shears Estimated From Floor Accelerations And Column Shears, Rakesh K. Goel

Civil and Environmental Engineering

This paper compares base shears computed from floor accelerations (inertial base shear) and column shears (structural base shear) for two mid-rise, multistory buildings due to a suite of 30 earthquake ground motions. The presented results demonstrate that the inertial base shear exceeds the structural base shear in the median by 10% to 20% and may exceed the structural base shear by as much as 70% for individual ground motions. Therefore, it is concluded that the inertial base shear computed from strong motion records should be used with caution to estimate the structural base shear.

Variability And Accuracy Of Target Displacement From Nonlinear Static Procedures, Rakesh K. Goel

Civil and Environmental Engineering

This paper compares the target displacement estimate from four current nonlinear static procedures—FEMA-356 CM, ASCE41 CM, ATC-40 CSM, and FEMA-440 CSM—with the value derived from recorded motions of five strongly shaken reinforced concrete buildings.This comparison provides useful insight into two important questions: (1) how much does the target displacement vary among the four nonlinear static procedures? and (2) can the engineering profession “accurately” predict the response of a real building during an earthquake event using currently available modeling techniques and pushover analysis procedures? It is shown that these procedures may lead to significantly different estimates of the target displacement, particularly …