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为明确同步注浆充填压力的大小及分布,利用流体力学理论对充填过程进行了理论分析。考虑到盾构推进速度较慢及浆液沿环向充填到最远距离所需的时间很短,假设同步注浆过程中,浆液仅沿环向充填盾尾间隙,即形成三维环形薄饼。分别在浆液为宾汉姆流体和牛顿流体条件下,推导了浆液充填压力沿盾尾间隙环向分布模型;并讨论了该模型的适用范围及主要参数的确定方法。用实际工程监测数据验证了该模型,并分析了浆液充填压力的分布规律及影响因素。分析结果表明:浆液充填压力环向分布模型的计算值与施工现场监测值吻合较好;浆液充填压力沿环向的变化主要由浆液自重的加压或减压作用、浆液剪切应力的减压作用两方面因素引起;浆液充填压力的宾汉姆流体计算值略小于牛顿流体计算值。
In order to clarify the size and distribution of filling pressure of synchronous grouting, the theory of fluid mechanics was used to analyze the filling process. Considering that the time required for the shield to advance slowly and the slurry to farthest in the circumferential direction is very short, it is assumed that during the synchronous grouting process, the slurry only fills the shield tail gap in the circumferential direction to form a three-dimensional annular pancake. The circumferential distribution model of slurry filling pressure along the shield tail gap was derived under the conditions of Bingham fluid and Newtonian fluid respectively. The applicable scope of the model and the method of determining the main parameters were discussed. The actual project monitoring data verify the model, and analyze the distribution of slurry filling pressure and influencing factors. The results show that the calculated value of the annular pressure distribution model is in good agreement with the monitoring value at the construction site. The variation of the filling pressure in the circumferential direction is mainly caused by the pressure or decompression of the self-weight of the slurry and the decompression of the slurry shear stress The action of two factors; the Bingham fluid filling pressure is slightly less than the calculation of Newtonian fluid.