David L. Allen

SOURCE ZONES, RECURRENCE RATES, AND TIME HISTORIES FOR EARTHQUAKES AFFECTING KENTUCKY

Time histories of hypothetical earthquakes, along with their peak-particle accelerations, and 0 and 5 percent damped response spectra are developed as guidelines for the seismic design of highway structures and bridges within Kentucky. The time histories are derived through the use of random vibration analyses, and take into consideration the probability of earthquakes from nearby seismic zones, the attenuation of ground motions with distance in the Central United States, and the possibility of a random event occurring outside of the generally recognized zones of seismicity in the area. Suggested peak-particle accelerations, time histories, and response spectra are intended for use at sites where the structure is assumed to be situated at the top of a bedrock foundation. For sites underlain by soils, and in particular for those sites underlain by poorly consolidated soils, it is recommended that site specific investigations be conducted by qualified professionals in order to determine the possibilities of frequency-dependent amplification (including resonance), damping, and soil failure when subjected to the suggested time histories. It should be noted that the seismic data is generated at the county seat and not at the county centroid.

Seismic Evaluation of the US41 Northbound Bridge over the Ohio River at Henderson, KY

The main objective of this investigation is to assess the structural integrity of the Ohio River bridge on US 41 Northbound at Henderson, Kentucky, when subjected to a projected 50-year earthquake. The investigation considers both the main bridge and the approach spans. To achieve the objective, the scope of the work was divided into the following tasks: (1) Field testing of the main bridge; (2) Finite element modeling and calibration; (3) Time-history seismic response analysis; and (4) Seismic response of the approach bridges using the response spectrum method.

SEISMIC EvALUATION OF THE OHIO RIVER BRIDGE oN US51 AT WICKLIFFE, KENTUCKY

This report presents the use of seismic evaluation of the Ohio river bridge on US51 at Wickliffe, Kentucky. The main bridge is a five-span single-deck cantilever through-truss type. The approach bridge has 21 spans on the Kentucky side and 6 span single-deck cantilever through-truss type. The approach bridge has 21 spans on the Kentucky side and 6 spans on the Illinois side. Although this bridge has not yet been subjected to a moderate or major earthquake, it is situated within the influence of the New Madrid seismic zone. The seismic evaluation program consists of field testing and seismic response analysis. The modal properties of the main bridge are determined through field testing, and are used to calibrate the three dimensional finite element model. The finite element model is then subjected to time histories of the 50-year earthquake event. Stresses and displacements obtained are within the acceptable limits. Analytical results indicate that the main bridge will survive the projected 50-year earthquake without significant damage and no loss-of-span. Hence, it is not recommended to retrofit the main bridge. The approach spans are analyzed using response spectrum method with simplified single-degree-of-freedom models. Most of the Kentucky and Illinois approach spans require additional anchor bolts at the bearings.

BARGE TRAFFIC ON KENTUCKY RIVERS

This report investigates barge traffic on all navigable waterways in Kentucky. The report provides the data necessary to develop the risk assessment procedures for Kentucky vessel impact design problems in accordance with the ASHTO Guide Specification and Commentary for Vessel Collision Design of Highway Bridges design method II. A computer program was written to process the database and calculate the probability based length, width, a capacity for each barge category. A second computer program was written to calculate the probability based number of barges in a flotilla column and row, and subsequently categorize the flotilla based upon the barge length and width categories designated by the U.S. Army Corps of Engineers. The equivalent static impact loads were then calculated using the probability based flotilla sizes and tonnages.

PROPOSAL FOR DEVELOPMENT OF A RESOURCE AND COMMODITY HIGHWAY SYSTEM.

In 1986, the Kentucky General Assembly established the Extended Weight Coal and Coal By-Products Haul Road System. The system includes approximately 3,200 miles of the most significant coal-haul roads in the state and permits coal trucks to carry much larger payloads than trucks with other commodities. In many ways, the extended-weight system has been very successful. Coal-transportation productivity has been substantially increased, and Kentucky coal continues to remain competitive in the marketplace. The study, conducted by the Kentucky Transportation Center, concluded that development of a statewide trucking network, herein named the Resource and Commodity Highway System, was both feasibile and desirable.

EVALUATION OF STONE COLUMN STABILIZED EMBANKMENT FOUNDATION

The purpose of this study was to document construction procedures, monitor field performance, and make recommendations as to the effectiveness and future use of the stone column procedure for foundation stabilization. This effort was executed by use of field inspections, photologs, instrumentation to monitor foundation and field response, and laboratory analyses of existing and possible conditions. Instrumentation included earth pressure meters, a multipoint settlement gage, a horizontal slope inclinometer, a settlement platform, and vertical slope inclinometers. Settlement of the foundation after column construction was observed to be approximately 9 in. (23 cm) as compared to the predicted total settlement of 16 in. (41 cm). Initial pressure distribution was affected by the stone columns but long term distribution indicated no relationship to the stone columns. Performance of the stone columns was judged to be satisfactory in that embankment stability was obtained.

Probabilistic Life Cycle Cost Analysis FHWA Demonstration Project DP 115

The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names and trade names are for identification purposes and are not to be considered as endorsements.

SEISMIC ISOLATION OF A HIGHLY SKEWED, PRESTRESSED CONCRETE GIRDER BRIDGE

A relatively new approach for designing or retrofitting highway bridges in seismic zones involves isolating the superstructure from the substructure. Through experimental and analytical investigations, this study evaluates the effectiveness of isolating one particular bridge: a highly skewed, prestressed concrete, slab-on-girder bridge. Dynamic testing of the bridge was performed using the pullback, quick-release method. A three dimensional finite element model of the bridge was created. It was refined, or calibrated, to match experimentally determined natural frequencies and mode shapes. Time-history analyses, using site-specific acceleration records, were conducted for the seismically isolated bridge model and an identical, non-isolated bridge model. For the bridge under consideration, seismic isolation was found to appreciably reduce forces that the bridge substructure and foundation must resist. Seismic design forces for pier columns were reduced between 43% and 86%. The results of this study clearly show that seismic isolation is an effective means of reducing earthquake forces on bridges.

DYNAMIC SITE PERIODS FOR THE JACKSON PURCHASE REGION OF WESTERN KENTUCKY

For this report, conventional seismic refraction and reflection techniques were used to determine the shear-wave velocities of the more poorly consolidated, near-surface sediments for a matrix of sites in the region. Conventional seismic P-wave reflections along with existing drill hole and seismic reflection data in the region were then used to determine the depth to the top of the bedrock at the sites investigated. These data were used in SHAKE91 to calculate the fundamental period of the ground motion at the sites. This period, identified in the study as the dynamic site period, is the period at which ground motions in the sedimentary column are most apt to be amplified as a result of a seismic shear wave propagating from the top of the bedrock to the surface. Based on the results in this report, it is recommended that bridges, overpasses, and other engineered structures built in the region be designed so that their natural periods do not coincide with the fundamental period of the sedimentary column, thereby avoiding damage during an earthquake as a result of in-place resonance.

Road Rater Correlation

In this study, a correlation has been conducted between the Model 400B and the Model 2000 Road Rater. Also contained in this study, is a study of the linearity of the Road Rater measurements. Information gained from this study will provide better understanding of Road Rater measurements.