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Baton Rouge, LA, United States

Chen X.,201 Capitol Access Road
Geotechnical Special Publication

Whitetopping refers to a thin Portland cement concrete (PCC) overlay on top of an existing deteriorated hot mix asphalt (HMA) pavement. When the PCC overlay slab thickness is between 5.1 and 10.2 cm, it is commonly referred to as ultra-thin whitetopping (UTW). In this study, the field performance of three in-service UTW sections, on US167, US65, and US90 in Louisiana were evaluated by means of pavement management system (PMS) data. The field performance survey results indicated that the cracking and patch distresses were few for these three UTW sections, which shows a good potential for UTW as an alternate rehabilitation technique for HMA pavement. The pavement condition was fair, good, and fair for US167, US65, and US90 after 13.5, 9.4 and 10.2 years of service, respectively, based on the Louisiana Department of Transportation and Development (LADOTD) PMS criterion for the national highway system. The fair pavement condition for US167 and US90 was mainly due to the relatively high international roughness index (IRI) and faulting values. © ASCE 2014. Source

Wang X.,Louisiana Tech University | Verma N.,Louisiana Tech University | Tsai C.,201 Capitol Access Road | Zhang Z.,Louisiana Transportation Research Center
Transportation Research Record

A new growth-rate-based model is proposed for pile setup prediction. Together with the Skov-Denver model, it has been developed for southern Louisiana clayey soils by using the pile driving analyzer database provided by the Louisiana Department of Transportation and Development from the construction of Phase 1B of the LA-1 relocation project in Leeville, Louisiana. The data used for this study include 115 restrike records from 95 production piles and the records of restrikes, static, and statnamic load tests of nine fully instrumented test piles. The models were developed with the average unit skin friction or normalized pile shaft resistances, which were obtained from the case pile wave analysis program analyses and the pile load test results. The growth-rate-based model can predict the capacity increase with time and can estimate the ultimate pile resistance. For the Skov-Denver model, selection of the reference time was investigated and distribution of the setup parameters A was studied. Predictability of the rate-based model was evaluated and validated by comparing it with the conventional Skov-Denver model. Source

Nickel C.,201 Capitol Access Road | Zhang Z.,Louisiana Transportation Research Center | Tsai C.,201 Capitol Access Road
Transportation Research Record

Hurricane Katrina severely damaged the I-10 Twin Span Bridges in New Orleans, Louisiana. Because these bridges are the primary evacuation route for the City of New Orleans, the design of the replacement bridges had to be done within a short time frame. The pile foundation of the bridges was designed with limited soil borings and cone penetration test (CPT) soundings, which resulted in a large amount of pile cut-off and potential undesirable pile buildups. The Louisiana Department of Transportation and Development (DOTD) was able to perform additional CPT soundings to define the soil conditions better during construction. Using these additional data, the Louisiana DOTD geotechnical engineer produced a more reliable design and avoided potentially costly construction claims. The problems encountered during construction and the improved pile foundation design are documented. Source

Yoon S.,201 Capitol Access Road | Tsai C.,201 Capitol Access Road | Melton J.,201 Capitol Access Road
Transportation Research Record

An instrumented pile load test was performed as part of the foundation design for the Caminada Bay Bridge project in south Louisiana. Both static and dynamic load tests were performed. The load-transfer curve of the test pile was obtained from strain measurements by using sister bar strain gauges at six locations along the pile shaft. The test pile resistance was determined by the Tomlinson method for cohesive soils and by the Nordlund method for cohesionless soils. The dynamic and the static load testing results indicated the test pile did not achieve the desired design resistance. The static analysis model was calibrated on the basis of observations of the pile load testing program. The design pile length was revised to benefit from the shallower scour depths for the revised pile design. The low resistance of the test pile resulted in the engineer's decision to use dynamic testing on the production piles to ensure adequate resistances. Taking advantage of the static load test of the instrumented test pile instead of simply using the smaller resistance factor from dynamic tests, the engineer combined the results of the two test methods and used a combination of resistance factors from both the static and dynamic load tests. This paper presents the evaluation of load test results and the rationale used for the selection of the resistance factor. Source

Yoon S.,201 Capitol Access Road | Tsai C.,201 Capitol Access Road | Garlington K.,201 Capitol Access Road
Geotechnical Special Publication

The failure of a slope along a segment of Highway 8 near Harrisonburg, Louisiana resulted in its partial closure in December 2008. The Louisiana Department of Transportation and Development needed to assess the damage and find a way to remedy the problem. Soil borings were taken and the slope was monitored using a vertical inclinometer. Then the aerial photos were used to evaluate the site conditions and map the progress of slope failure over time. Further, a series of laboratory tests were performed on the samples obtained by boring from the site to determine the stress path followed by the soil which led to the slope failure. Laboratory testing program included conventional unconsolidated undrained (UU) triaxial tests, multistage consolidated undrained (CU) triaxial tests, and K o-consolidated undrained (CKoU) triaxial lateral extension tests. Using the extensive laboratory test results, the soil design parameters were selected for slope stability analyses. The limit equilibrium analyses showed different results based on parameters obtained from different stress path testing. Further, partial stabilization at the toe of the slope was recommended as the most suitable remedial measure. © 2010 ASCE. Source

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