Model Test Of Lattice Shaped Diaphragm Wall As Bridge Foundation

Lattice shaped diaphragm wall as bridge foundation has shown good work efficiency、 low cost and wide application range. It can receive more intuitive and reliable conclusions using model tests to study the bearing behavior and settling characteristics of lattice shaped diaphragm wall as bridge foundation in soft soil. This provides a scientific basis for engineering design and construction of the diaphragm wall foundation as well.This paper developed the model test based on similarity principle. The plan has been designed and the model test has been implemented according to the plan. Analysis Based on the test results shows the following conclusions:①Pile group foundation and two-compartment diaphragm wall foundation show gradually varied load-settlement curves. The ultimate bearing capacity of pile group is lower than two-compartment diaphragm wall. The settlement of pile group is bigger than two-compartment diaphragm wall through the whole loading process as well.②Pile cap settles along with the silt clay under it, decreaseing the relative displacement between the silt clay and the piles, causing the side friction of the pile group foundation in the silt clay do not obviously through the whole process. The curve of the side friction of the pile group showed "L" pattern, while the curve of the side friction of the two-compartment diaphragm wall showed "M" pattern.③According to the analysis of the curves of load sharing ratio, the pile group foundation and the two-compartment diaphragm wall foundation can be determinated as "friction and end-bearing piles".④Under the same load, the pile group foundation produce bigger unit end resistance, leading to a bigger settlement during the loading progress.Comparing the features of the two foundations in the structure, we found that in the same condition of concrete quantity, two-compartment diaphragm wall foundation can better play the characteristics of settlement control and bearing behavior. Lattice shaped diaphragm wall foundation in alternative pile group will improve the bearing capacity and decrease settlement etc.