Theoretical Calculation And Research On Soil Arching Effect In Excavation Correction

During the natural building settlement,excessive inclination of building seriously affecting the safety and use of residents,because samll building distance and design errors.Sallow horizontal excavation soil landing rectifying method is economic and practical,and it is widely used in building rectification.Recent study consider that the additional settlement of the shallow horizontal excavation soil landing rectifying method is mainly attributed to the deformation of the soil hole,and the soil arch effect is rarely studied.In order to study the phenomenon that the soil arch effect hinders the deformation of soil in the shallow horizontal excavation soil landing rectifying method,this thesis analyzes the vertical deformation of the hole top and the stress distribution around the hole combined with recent study,and a experiment is designed to analys the stress of soil hole under conditions of 200 mm hole diameter and 500 mm depth.The main research contents icclude:1.In order to study the phenomenom that stress redistribution and stress concentration in sallow horizontal excavation soil landing rectification process,this thesis analyzes the calculation formula of the deformation of soil hole in the shallow horizontal excavation with the recent calculation method and analyzes of the stress state of the plastic zone between soil holes.The foundation settlement is divided into two parts soil compression deformation and vertical displacement of the top of the hole.The calculation formula of foundation settlement under the influence of soil arching effect is given.2.In order to study the phenomenom that stress redistribution and stress concentration in sallow horizontal excavation soil landing rectification process,a model test is designed and made.This thesis adopt recation beam to apply uniform load and excavate soil on the 200 mm aperture and 500 mm depth,and the development curve of the hole stress change and aperture deformation is obtained.The results show that the stress at the side of the excavation hole increases to about twice the initial stress,and the stress of hole top decreases.It is proved that the soil arch effect in the horizontal excavation rectification makes the stress redistributio.around the soil hole.3.A three-dimensional finite element model is established based on the experimental data to analyze the influence of soil arch effect on the stress distribution around the hole under different hole radius,hole spacing and buried depth.The results show that the maximum stress region is not superimposed when the hole spacing is 600 mm and 100 mm,and the hole spacing is more than 3 times the hole diameter.When the pore spacing of 600 mm is 200 mm,the maximum stress area begins to stack,and the hole spacing is equal to three times the hole size.