Analysis Of The Interaction Between Structural Piles And Caisson During Constructing In A Water Plant

With the continuous development of the city,the land for municipal facilities is often tight.A large number of caisson structures need to be surrounded by enclosure structures to strictly control the impact of the sinking of the caisson on the surrounding environment.The pile foundations of the structures around the caisson often need to be set up next to the caisson.This study relies on Yingshang County Urban Surface Water Plant project.And MIDAS-GTS NX is used to establish the structure model of the sinking progress of the caisson to study the force of the wall under the sinking condition of the caisson,and the enclosure effect of high pressure rotary jet grouting piles with different pile diameters and pile lengths on surrounding environment,as well as the influence of construction sequence of caisson and surrounding pile foundation on its stress.(1)The comparative analysis of the numerical simulation analysis of the sinking construction of the caisson and the theoretical calculation results shows that the stress of the caisson wall calculated by the classical earth pressure theory in the engineering design calculation is greater than the stress calculated by the numerical simulation.(2)Numerical analysis and comparison of the conditions of whether there are high-pressure rotary jet grouting piles around the caisson show that setting up a high-pressure rotary jet grouting pile enclosure structure around the caisson has a significant effect on the surrounding environment outside the caisson.The comparative analysis of the single-variable change of the pile length or pile diameter of the high-pressure rotary jet-grouting piles shows that the high-pressure rotary jet-grouting pile length exceeds a certain length of the bottom of the caisson blade to have a significant enclosure effect,and the enclosure effect varies with the pile length increases,but when the pile length reaches a certain length,increasing the pile length has no obvious trend to improve the enclosure effect.The increase in the pile diameter has a certain effect on the improvement of the surrounding environment enclosure effect,but the effect is not obvious.(3)In order to study the influence of the construction sequence of the caisson and surrounding pile foundations on the structure of the adjacent previous construction,a numerical model was established for the caisson and surrounding bored pile foundations.It shows that when the bored pile is constructed first,the sinking process of the caisson will produce a relatively large pull-down load on the pile foundation in a certain range around the caisson.The closer the pile foundation is to the caisson,the greater the load,and the more obvious the tendency to increase with the sinking of the caisson,it will cause damage to the pile foundation in severe cases.a After the first sinking of the caisson is completed,the impact of the pile forming process of the bored pile on the bending moment and stress of the caisson wall is almost negligible.