A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Field Instrumentation and Testing to Study Set-up Phenomenon of Piles Driven into Louisiana Clayey Soils
This research study aims to investigate the pile set-up phenomenon for clayey soils and develop empirical models to predict pile set-up resistance at certain time after end of driving (EOD). To fulfill the objective, a total number of twelve prestressed concrete (PSC) test piles were driven in different soil conditions of Louisiana. Detailed laboratory and in-situ soil testing were performed at each test pile location in order to characterize the subsurface soil condition. Dynamic load tests and static load tests were performed at different times after EOD to verify the axial resistances of piles and to quantify the amount of increase in resistance (i.e., set-up) compared to the EOD. The focus of this research was to calculate the resistance of individual soil layers with time along the length of the pile. In order to implement this goal, all the test piles were instrumented with vibrating wire strain gages. The measurements of vibrating wire strain gages were used to measure the distribution of load transfer along the length of the pile during the static load tests. Vibrating wire piezometers and pressure cells were also installed in the pile face in order to calculate the time for dissipation of excess pore water pressure and corresponding increase in effective stress with time. Case Pile Wave Analysis Program (CAPWAP) was performed in all the dynamic load test data and used to calculate the side resistance of individual soil layers along the length of the pile during dynamic load tests. Logarithmic set-up parameter “A” of individual soil layers were calculated using the unit side resistance. The set-up parameter “A” was correlated with different soil properties such as undrained shear strength, plasticity index, coefficient of consolidation, sensitivity and over-consolidation ratio (OCR). Three different levels of empirical models were developed to estimate the magnitude of pile set-up with time. The developed models were used to predict the total resistance of piles in the database at four different time intervals (i.e., 30 days, 45 days, 60 days and 90 days) after EOD. Reliability analyses were performed to calibrate the set-up resistance factor (ϕset-up) for incorporating it into the LRFD pile design methodology. Accordingly, a set-up resistance factor (ϕset-up) of 0.35 is recommended. A framework for estimating the duration of pile set-up based on consolidation theory of soils at the pile face was Introduced.
Field Instrumentation and Testing to Study Set-up Phenomenon of Piles Driven into Louisiana Clayey Soils
This research study aims to investigate the pile set-up phenomenon for clayey soils and develop empirical models to predict pile set-up resistance at certain time after end of driving (EOD). To fulfill the objective, a total number of twelve prestressed concrete (PSC) test piles were driven in different soil conditions of Louisiana. Detailed laboratory and in-situ soil testing were performed at each test pile location in order to characterize the subsurface soil condition. Dynamic load tests and static load tests were performed at different times after EOD to verify the axial resistances of piles and to quantify the amount of increase in resistance (i.e., set-up) compared to the EOD. The focus of this research was to calculate the resistance of individual soil layers with time along the length of the pile. In order to implement this goal, all the test piles were instrumented with vibrating wire strain gages. The measurements of vibrating wire strain gages were used to measure the distribution of load transfer along the length of the pile during the static load tests. Vibrating wire piezometers and pressure cells were also installed in the pile face in order to calculate the time for dissipation of excess pore water pressure and corresponding increase in effective stress with time. Case Pile Wave Analysis Program (CAPWAP) was performed in all the dynamic load test data and used to calculate the side resistance of individual soil layers along the length of the pile during dynamic load tests. Logarithmic set-up parameter “A” of individual soil layers were calculated using the unit side resistance. The set-up parameter “A” was correlated with different soil properties such as undrained shear strength, plasticity index, coefficient of consolidation, sensitivity and over-consolidation ratio (OCR). Three different levels of empirical models were developed to estimate the magnitude of pile set-up with time. The developed models were used to predict the total resistance of piles in the database at four different time intervals (i.e., 30 days, 45 days, 60 days and 90 days) after EOD. Reliability analyses were performed to calibrate the set-up resistance factor (ϕset-up) for incorporating it into the LRFD pile design methodology. Accordingly, a set-up resistance factor (ϕset-up) of 0.35 is recommended. A framework for estimating the duration of pile set-up based on consolidation theory of soils at the pile face was Introduced.
Field Instrumentation and Testing to Study Set-up Phenomenon of Piles Driven into Louisiana Clayey Soils
M. Y. Abu-Farsakh (author) / N. Haque (author) / Q. Chen (author)
2016
179 pages
Report
No indication
English
Soil Sciences , Soil & Rock Mechanics , Natural Resource Management , Hydrology & Limnology , Field instrumentation methods , Piles(Foundation) , Louisiana Department of Transportation and Development , Clayey soils , LRFD design methods , Soil science , Soil layers , Piezometers , Water pressure , Empirical models , Methodologyy , Soil properties , Soil condition , Plasticity index , Dynamic load tests , Recommendatiions , Baton Rouge (Louisiana)
Study of Pile Setup: Southern Louisiana Clayey Soils
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