Deformation Mechanism And Its Control Strategy For Water-rich Sand Stratum In Tunnels Of Qingdao

Taking Qingdao subway tunnel case as example, theoretical analysis, laboratory tests and fieldtests were used to research on the engineering characteristics of Qingdao water-rich sand stratum. Itwas found that Qingdao sand was of high clay content and intensity, and the sand layer was thin, also,tunnel construction was often under a particular condition of soil-rock compound strata. Numericalsimulation and physical model experiment were combined to simulate the deformation processduring the tunnel excavation of water-rich sand stratum, and convergence deformation analysis,stress state constraints, extrusion and binding contrast judgment method were combined to analyzethe stability of Qingdao water rich-sand stratum tunnel, thus, it was revealed that the high-strengthsand layer is the most main damage factor of deformation mechanism. Considering practicalengineering, the corresponding control countermeasures were put forward, and it was pointed outthat ADECO-RS had a good control effect on the tunnel deformation of rich-water sand stratum bystrengthening core soil of tunnel face in advance. Also, the construction control technology ofADECO-RS was studied, and compressive strength tests and monitoring measures were adopted toanalyze the applicability of ADECO-RS, so, it was further verified that ADECO-RS was effectiveand that strata uplift and pile Angle control were key for construction control.