The Influence of Soil Surrounding the Caisson Cutting Edge to Excavation and Sinking

摘要

In the process of excavation and sinking of the open caisson, there is a risk that the excavation quantity is too large to cause the influx of the lateral soil of the open caisson to the inside of the borehole wall. Which caused the gushing sand or sudden sinking of excessive sudden situation. The bearing capacity of the soil surrounding the open caisson cutting edge is the key factor of the excavation settlement and the limit of mud height. This article is based on the finite element numerical simulation, by controlling the variable method, with cohesive force and angle of internal friction of the soil surrounding the open caisson cutting edge as variables, analyzed the impact on the excavation of the open caisson sinking. Analysis the influence factors of the internal friction angle as the main. At the same time, through curve fitting of angle of internal friction, the excavation settlement and mud height to the change of the relations, and determined the limit mud height of this calculation model. The results show that the soil cohesion at the cutting edge has an effect on the total sedimentation under the caisson load, and the effect of the total amount of the excavation is small. During the process of sinking, the friction angle of the soil at the cutting edge has a great influence on the total sedimentation under the caisson load and the total amount of excavation. The larger the internal friction angle is, the smaller the total sedimentation under the caisson load, the larger the total settlement of the caisson excavation, the smaller the height of the caisson mud surface, and the smaller the decrease of the mud surface. The internal friction angle and the initial mud surface height satisfy the first order linear relationship, and the total settlement of the excavation also satisfies the first order linear relationship. The total amount of excavation and excavation meet the second-order linear relationship. The total amount of excavation and excavation in different soil layers can be calculated by using the formula given in this paper, and the maximum excavation and mud surface limits are calculated.