Study On Identification Of Slurry Saturation Behind Tunnel Wall By Wavelet Analysis And Ground Settlement

During tunnel excavation,the stress redistribution of the stratum caused by excavation disturbance will affect the support around the tunnel.When the slurry for supporting around the tunnel is not full or the strength is not enough,the ground settlement will increase accordingly and have an adverse impact on the safety of the tunnel.In order to ensure the safety of the tunnel and ground buildings,it is necessary to analyze the plumpness of the supporting slurry around the tunnel,so as to obtain the plumpness and under plumpness position of the slurry behind the wall,which has important theoretical significance and practical application value for improving the quality of tunnel construction.Aiming at the problem of the plumpness of the slurry behind the tunnel wall,a threedimensional finite element model of the under plumpness of the slurry behind the tunnel wall is established by using the finite element method.Using the agility of wavelet analysis on physical parameters such as structural stiffness and damage identification ability,wavelet analysis is applied to explore the relationship between the under plumpness of the slurry and ground settlement.The modal parameters of the model are obtained by numerical calculation,and the modal parameters are obtained by wavelet transform.Based on this,the location of the singularity and the size of the crest are judged.The location of the singularity is the location where the slurry behind the wall is not full,and the size of the crest reflects the degree of the slurry behind the wall is not full.The relationship between the peak value and the unsatisfied degree in different ranges is obtained by function fitting the peak value and under plumpness the wavelet coefficient diagram.Then,the function relationship between the increase rate of ground settlement and the unsatisfied degree in different ranges of slurry behind the wall is obtained by fitting the increase rate of ground settlement with the under plumpness.On the basis of the above simulation research,aiming at the shield tunneling entity project,the identification of different under plumpness in different ranges and the relationship between the under plumpness and ground settlement are studied by using the backwall slurry under plumpness model.Based on the 11 bid section of Changsha Metro Line 3,the method established in this paper is used to carry out numerical simulation verification and Analysis on the identification of the grout under plumpness around the tunnel and the relationship between the under plumpness and ground settlement.The under plumpness position and degree of the grout behind the 11 bid section wall and the increase of ground settlement are given,which verifies the correctness and feasibility of the method proposed in this paper,The proposed wavelet analysis method for identifying the degree of under plumpness can provide a reference for engineering applications.