Using the results from three full-scale lateral pile group load tests in stiff clay with spacing ranging from 3.3 to 5.65, computer analyses were performed to back-calculate p multipliers. The p mu...

Pile Spacing Effects on Lateral Pile Group Behavior: Analysis

This paper presents the results of static lateral load tests carried out on 1×2 , 2×2 , 1×4 , and 3×3 model pile groups embedded in soft clay. Tests were carried out on piles with length to diameter ratios of 15, 30, and 40 and three to nine pile diameter spacing. The effects of pile spacing, number of piles, embedment length, and configuration on pile-group interaction were investigated. Group efficiency, critical spacing, and p multipliers were evaluated from the experimental study. The experimental results have been compared with those obtained from the program GROUP. It has been found that the lateral capacity of piles in 3×3 group at three diameter spacing is about 40% less than that of the single pile. Group interaction causes 20% increase in the maximum bending moment in piles of the groups with three diameter spacing in comparison to the single pile. Results indicate substantial difference in p multipliers of the corresponding rows of the linear and square pile groups. The predicted field group be...

Group interaction effects on laterally loaded piles in clay.

Numerical simulation and analytical modeling of pile-supported structures subjected to ship collisions including soil–structure interaction

To investigate group interaction effects as a function of pile spacing, full-scale cyclic lateral load tests were performed on pile groups in stiff clay spaced at 3.3, 4.4, and 5.65 pile diameters in the direction of loading with as many as five rows of piles. Group interaction effects decreased considerably as pile spacing increased from 3.3 to 5.65D . Lateral resistance was a function of row location in the group, rather than location within a row. For a given deflection, the leading (first) row piles carried the greatest load, while the second and third row piles carried successively smaller loads. Fourth and fifth row piles carried about the same load as the third row piles. For a given load, the maximum bending moments in the trailing row piles were greater than those in the lead row, but these effects decreased as spacing increased. Cyclic loading reduced the peak load by about 15% after 15 cycles; however, distribution of load within the pile group was essentially the same as at the peak load. Gaps...

Pile Spacing Effects on Lateral Pile Group Behavior: Load Tests

http://ssi.civil.ntua.gr/downloads/journals/2012-C&G-Cyclic%20Lateral%20Response%20of%20Piles%20in%20Dry%20Sand%20.Finite%20Element%20Modeling%20and%20validation.pdf

Cyclic lateral response of piles in dry sand: Finite element modeling and validation

Static and dynamic lateral load tests were performed on four full-scale pile groups driven at four different spacings. P-multipliers to account for group interaction effects were back-calculated for each test. P-multipliers were found to be a function of row position within the group but were independent of position within a row. Curves were developed to define p-mulipliers as a function of pile spacing. Using these p-multipliers along with soil properties obtained from site characterization work, excellent agreement between measured and computed response could be obtained. Dynamic load tests were performed using the Statnamic load system. Dynamic lateral resistance was consistently higher than the measured static resistance, however, resistance was dynamic resistance was greater for the virgin load than for reloading. Simple one degree-of-freedom models were successfully used to interpret the static load-deflection curve from the dynamic load-deflection curves. These analyses indicate that the increased dynamic lateral resistance was largely due to damping.

https://rosap.ntl.bts.gov/view/dot/27636/dot_27636_DS1.pdf

Ryan J. Olsen

Papers

Pile Spacing Effects on Lateral Pile Group Behavior: Analysis

Pile Spacing Effects on Lateral Pile Group Behavior: Load Tests

Response, Analysis, and Design of Pile Groups Subjected to Static and Dynamic Lateral Loads