Changing the redistribution of forces between pile foundation elements as the load increases

Abstract

Having, during the design of the pile foundation, the load-bearing capacity of the piles determined in one way or another, as well as the calculated resistance under the sole of the rostwerk as a shallow foundation, it is possible to use data on the degree of implementation of the load-bearing capacity of each of the elements of the pile foundation to arrive at its total load-bearing capacity. But it is known that at different stages of loading, the degree of implementation of the load-bearing capacity of the elements of the pile foundation can change.The purpose of this work is to analyze the change in the redistribution of forces between the elements of the pile foundation with a gradual increase in the loads on it. This will make it possible to justify the selection of the critical value of settlement, for which it is appropriate to determine the degrees of implementation of the load-bearing capacity of the elements of the pile foundation, which can be proposed for use in the design.The analysis of changes in the redistribution of forces between the elements of the pile foundation with a gradual increase in loads on it was performed for the bush pile foundation based on physical modeling on small-scale models, as well as mathematical modeling using the Plaxis software complex.It was established that the pile in the composition of the bush, both according to the results of physical modeling and mathematical modeling, gradually realizes its load-bearing capacity as the load increases and, with significant values of settlement, perceives the load, more than the limit load of a single pile.Therefore, at a certain stage of loading, the degree of implementation of the bearing capacity of the pile begins to exceed unity. The share of the rostwerkwork in the load-bearing capacity of the foundation increases as the load increases, as the pressure under the sole of the rostwerkwork increases. The degree of implementation of the rostwerk practically does not change for a sandy base and increases insignificantly for a clay base. So, the rostwerk is gradually included in the work, but the potential ability of the rostwerk to perceive the load is not fully realized and at a certain value of settlement remains constant.The possibility of analyzing the redistribution of forces between elements of the pile group only at the stage of the maximum allowable settlement was evaluated.