Study On Behavior Of Battered Piles Under Inclined Load

Battered pile and pile group are generally used in bridge, wharf and foundation of transmission power. As the limitation of equipment and technology of construction, some vertical piles are constructed to battered piles. There is less research about bartered pile and pile group. In this paper the "generalized elastic theory" is proposed to solve the problem. A series of model experiments and prototype experiments are run to explore the technology of transmission power foundation.Based on the elastic theory, the stress between the pile and the soil is assumed to be a function of the relative displacement. The model is called "generalized elastic theory" in this paper, which can take the plastic behavior of the soil around the pile into account, and also can analyze the battered pile and pile group.First, the generalized elastic theory is employed into in single pile analysis. The degeneration solution is accordant with Poulos' results. Analyzing the load-displacement behavior of the battered pile, the results agree well with Meyerhof's model experiments and ZhangLM's centrifuge experiments. Then the author gives the method to determine the parameters of the generalized elastic theory. Computing examples show that the bearing capacity of the piles depend on the load inclination and the pile battered angle. Under the vertical load, the vertical pile has bigger bearing capacity than the battered pile. Under the lateral load, the positive battered pile has bigger bearing capacity than the vertical and the negative pile. The allowable settlement of the pile head is suggested and the vertical pile can bear load with inclination of less than 10 , and the battered pile bearing vertical load can be angle of less than 10 .Then the paper employed the generalized elastic theory in pile group, considering the interaction between pile-soil. Some examples are analyzed and indicate that along with the increasing load the distribution of axial load and rigidity of single pile become uniform. Compared with various types of pile group, the pile group in circle distribution contributes to bear inclined load, and the axial load of each pile is more uniform. Under the vertical load, the vertical pile group has bigger bearing capacity than the battered pile group. Under lateral load, the positive battered pile group has bigger bearing capacity than the vertical and negative battered pile group.Both model experiments and prototype experiments are conducted. The model experiments results indicate that the pile group composed of extending all around piles can bear inclined load better. This is beneficial to the foundation of transmission tower. The prototype experiments results indicate that the micropile's load capacity is satisfied with design. The efficiency of the pile group is about 0.9. According to the geology of experiments, the results of presented method agree well with those of theexperiments. This further proves that the generalized elastic theory is reasonable and reliable.