PileLAT Validation Examples
This validation example presents a case study for the test piles driven into interbedded sand and stiff clay layers based on the single pile testing results reported in Rollins et. al. (2006).
The soil profile generally consists of over-consolidated stiff clays with some sand layers to a depth of 5 m. The sand layers are in a medium compact density state. Groundwater is located a t a depth of 1.07 m during the testing. The stiff clay is underlain by softer sensitive clays which are in turn underlain by interbedded layers of silty clay and sand.
This example reports a case study for laterally loaded piles in soils with both cohesion and friction (c-phi soils) using the PileLAT program. The example problem from Mokwa et al. (2000) with the title of "Development of p-y curves for partly saturated silts and clays" is used in this case study.
The lateral displacement of pile foundation often shall be checked in the routine foundation design and the geotechnical engineers need to ensure that the relevant displacement compliance criterion can be satisfied. It is a general practice to ignore the P-Delta effect in the pile design with performing first-order analysis as the displacement criterion of limiting the pile deflection to within the range of 20 to 25 mm acts as a means to control the P-delta effect.
However, it would be very useful if the analysis of P-Delta effect can be readily carried out in the design process where the piles can be designed according to the analysis results. As a result, the limiting criterion on the allowable displacement can be relaxed or waived entirely if the structural capacity is found adequate.
This validation example demonstrates that PileLAT program correctly includes the P-Delta effect in the analysis of bending moment for laterally loaded piles under axial loading.
This validation example presents a case study with using PileLAT program for a pile lateral load test carried out in Salt Lake City in 2003.
The test single steel pipe pile had an outside diameter of 324 mm and a wall thickness of 9.5 mm. The modulus of elasticity for the steel is 200 GPa. The moment of inertia (I) of the pile is 1.17 x 10^8 (mm^4). The soil profile consists of stiff clays with some sand layers underlain by soft clays. The water table was located 1.3 m below the excavated surface.
To demonstrate the reliability of our PileLAT program, we modeled the full-scale single pile lateral load test documented by Christensen (2006) at Brigham Young University. This benchmark case provided an excellent opportunity to validate the program against high-quality field data, with results that closely matched the measured responses.