Effects of dead loads on the lateral response of battered pile groups

Abstract

The effects of vertical load on the lateral resistance of single piles were initially reviewed to facilitate the interpretation of the test results of pile groups. Then, 18 different lateral load tests were carried out in the centrifuge on the 3 × 3 and the 4 × 4 fixed-head battered pile groups to investigate the effects of vertical load on the group lateral resistance. Vertical dead loads ranging from approximately 20 to 80% of the vertical ultimate group capacity Puv were applied. Based on these tests, the effects of vertical dead load on the lateral resistance of the battered pile groups are found to depend on pile arrangement, pile inclination, and soil density. The lateral resistances of the 3 × 3 pile groups do not appear to vary considerably with the vertical dead loads in the range of the vertical loads studied. For the 4 × 4 pile groups however, the lateral resistances at vertical loads of approximately 50 and 80% Puv may be 26-29% and even 40% higher than that at the 20% Puv dead load. It may be inferred that designs based on standard lateral load tests with small vertical dead loads would be on the safe side. Three mechanisms for vertical load effects are discussed in terms of axial tension and compression failures, influence of pile inclination, and initial subgrade reaction caused by vertical loading. Preliminary numerical analyses are also performed to simulate the responses of some of the battered pile groups.Key words: pile group, battered pile, lateral resistance, load test, pile-soil interaction, centrifuge test.

Numerical analysis of the response of battered piles to inclined pullout loads

“…It can be observed that the increase in the load inclination in both forward and reverse directions results in a reduction in both the pile stiffness and pullout capacity. This influence is similar to that reported for vertical piles [1,3,4,10,17]. pile stiffness and pullout capacity.…”

“…The design of battered piles requires a good understanding of their response to inclined loads, in particular their pullout capacity. This issue was investigated for compressive inclined loads using centrifuge tests [1][2][3][4], which showed that the inclination of both the pile and the load affected the piles bearing capacity. Results indicated that the bearing capacity of a batter pile is less than that of a vertical pile, and that inclination of the load resulted in a decrease in 1278 H. MROUEH AND I. SHAHROUR the bearing capacity of piles.…”

Vertical loads effect on the lateral pile group resistance in sand

“…Other related research on single piles includes (Zhukov andBalov 1978, Zhang et al 1999). Zhang et al (2002) through centrifuge experiments on 3 × 3 and 4 × 4 fixed-head battered pile groups concluded that the effects of vertical load on the lateral resistance of 3 × 3 pile groups were not significant. For 4 × 4 pile groups however, the lateral resistances increased significantly with vertical loads.…”

Variational solution for the effect of vertical load on the lateral response of offshore piles

“…For example, Anagnostopoulos and Georgiadis (1993) investigated the interaction among the axial and the lateral responses of piles in clay with model tests. Zhang et al (2002) investigated the effects of the vertical load on the group lateral resistances by centrifuge model test. They pointed out that the influence of the vertical loads is closely linked to the pile-soil system.…”