幂律型浆液扩散压力环向分布模型

为研究幂律型浆液注浆时注浆压力的变化情况,考虑盾尾断面新注入浆液与已注入浆液间阻碍作用,假设壁后注浆时盾尾形成三维环形空隙,提出了幂律型浆液扩散压力环向分布模型,并利用流体力学理论推导了幂律型浆液扩散压力环向分布式,分析了公式适用范围以及各参数的实际意义。与实际工程数据对比,验证了模型和计算式的正确性。结果表明,计算式可以反映注浆时环向分布各个位置压力值的大小;当公式中稠度系数n=1时,该式即为牛顿流体计算式,环向压力扩散模型同样适用,且幂律型流体环向扩散压力小于牛顿流体;受浆液自重影响,注浆孔注浆时向上表现为减压,向下表现为加压;压力环向分布断面呈现出上窄下宽的不规则环形;同一注浆孔幂律型浆液水灰比越大,浆液扩散压力越小。

Power law model of annular distribution of slurry diffusion pressure

To study the power law type slurry grouting grouting pressure change,considering the new injection shield tail section between grout and has injection grout effect,in the case that the wall grouting shield tail at form 3 d annular clearance,put forward the power law model grout diffusion pressure ring to distribution model,and using the theory of fluid mechanics was deduced to distributed power law type grout diffusion pressure ring,analyzes the scope and the formula parameters of practical significance to compared with the actual engineering data,verify the validity of the model and the calculation formula results show that the calculation formula can reflect the grouting in toroidal pressure value size distribution of each position;When the consistency coefficient n=1,the formula is the Newtonian fluid formula,and the annular pressure diffusion model is also applicable.The annular diffusion pressure of power law fluid is less than that of Newtonian fluid.Under the influence of grout weight,the upward expression of grouting hole is pressure reduction,and downward expression of grouting hole is pressure.The distribution section of pressure ring presents an irregular ring with upper narrow and lower wide.The larger the water-cement ratio is,the smaller the slurry diffusion pressure is.