Mechanism Analysis And Treatment Technology Of Floor Heave In Railway Tunnel

With the rapid development of railway in C hina,the scale and quantity of railway tunnel construction are increasing day by day.Because of the tunnel the geological environment is complex and changeable,floor heave occurs frequently,seriously affecting the railway operation and construction safety,therefore,to carry out research on heave mechanism and remediation technology has important theoretical significance and practical value for railway tunnel bottom.In this paper,aimed at the railway tunnel floor heave diseases,the mechanism of tunnel floor heave and its remediation techniques are investigated,through field investigation,theoretical analysis and numerical simulation.The main influencing factors,causes and mechanism of tunnel floor heave a re analyzed statistically.The influence of different influencing factors on the deformation and stress of the bottom of tunnel was studied.The treatment measures of tunnel floor heave disease are put forward.The main research contents are as follows:(1)The main influencing factors,causes and mechanisms of tunnel floor heave are analyzed statistically.Through the investigation of 10 railway line 18 tunnel floor heave disease statistics,the main influencing factor of tunnel floor heave,followed by groundwater,construction quality,expansion matching and stress,rock structure,analysis of the progressive evolution of tunnel floor heave.The floor heave of a tunnel is closely related to time,which occurs after a certain range of rock failure occurs at the bottom of the surrounding rock..(2)The influence of different influencing factors on the deformation and stress of the bottom of tunnel was studied.Through the finite element software to simulate the tunnel floor heave of bottom structure deformation and stress distribution,invert filling layer top surface is basically the tension,and the center ditch sides and filling middle position top tensile stress is larger,and from top to reduce internal structure.At the bottom of the structure deformation and stress change with the different effects of the factors analysis,the influence of various factors on the bottom of the structure deformation and stress,followed by expansion force,arch span ratio,arch thickness and rock deterioration.(3)The measures for renovating the floor heave of railway tunnel are put forward,and the technical characteristics,scope of application and key parameters are clarified.Bolting integration through interaction between bolt and slurry,improve the integrity of rock bottom and cut off the ground;the light well point precipitation + grouting to lower the water level,improve the bearing capacity of surrounding rock at the bottom of the tunnel bottom;by demolishing the existing basement structure and strong design,improve the structure of basement for resistance;fill in by the replacement of adverse formation,improve the ability to resist deformation of the surrounding rock bottom.(4)The Shiziling tunnel bottom drum disease as an example,combined with the tunne l's own structure,put forward the sunken beam long distance overhead line refoot measures,formed the construction organization design Co.skylight time.The tunnel longitudinal beam suspension scheme construction convenient and the longitudinal and trans verse beam system is stable and reliable,the realization of the finite time long distance from excavation roof line all overhead,multiple simultaneous rapid excavation construction to ensure the safe operation of changing,and has achieved good effect of engineering.