盾构施工中风化花岗岩地层粘性参数测定分析

Determination and Analysis of Viscous Parameters of Weathered Granite Formation During Shield Tunneling

在粘性土地层中泥水盾构掘进施工时,地层自造浆能力强,泥浆粘度会快速增加,过高的泥浆粘度易导致刀盘结泥,影响盾构正常掘进。在进行盾构选型时,会根据地层的粘性程度来选择刀盘结构及冲刷体系;而在实际施工过程中,需要通过控制泥浆指标来缓解刀盘糊泥的情况。将地勘资料中表征地层粘性指标的粘聚力和塑性指数大小与刀盘结泥的情况的程度进行对比,发现结泥情况与勘察报告给出的地层粘性指标并没有对应关系,不能很好地根据该地层参数进行盾构机选型以及提前对泥浆指标进行干预。

During the construction of mud shield tunneling in viscous soil layer,the mud viscosity will increase rapidly due to the strong self-grouting ability of the formation.Excessive slurry viscosity can easily lead to cutter head slurry and affect normal shield tunneling.When selecting shield tunneling,cutter head structure and scouring system will be selected according to the viscous degree of strata.In the actual construction process,it is also necessary to control the mud index to alleviate the situation of cutter head mud.In this paper,by comparing the cohesion and plasticity index of stratum viscous index represented in geological prospecting data with the degree of mud deposit in cutter head,it is found that there is no corresponding relationship between mud deposit and formation viscous index given in investigation report.Shield tunneling machine selection and mud index intervention can not be carried out well according to the formation parameters.