Abstract：During rectangular pipe jacking tunnel construction,in order to study thixotropic mud holster and effect of reducing resistance,different overburden pressures and mixture ratios of slurry and soil were designed to study the diffusion radius and friction coefficient of slurry in sandy soil cohesive soil by simulation experiment. The results showed that: initial grouting pressures are nearly 80% of overburden pressure while it is linear growth between grouting pressure and overburden pressure in sandy soil; in cohesive soil,initial grouting pressures are nearly 2 times of overburden pressure,effect of thixotropic mud holster is poor due to fracturing diffusion and non-uniform seeping; the maximum friction coefficient of single thixotropic mud holster is0. 011 8,and the corresponding friction angle is 0. 68°; the effect is weakened with increasing of cohesive soil count. The maximum jacking force of measuring in situ is reduced by 60% of theoretical value,so it was applied well.

Keyword：mud holster;grouting pressure;effect of reducing resistance;pipe jacking tunnel;