富水砂层土压平衡盾构渣土改良应用研究

Study on soil pressure-balance shield tunneling residual soil improvement in water-rich sand bed

在盾构施工过程中,通常要求刀盘范围内的土体具有一定的流塑性和低渗透性,但实际施工时,土体条件往往不具备这种特性。为此,需要对刀盘范围进行改良。文章从土压平衡盾构机的工作原理着手,分析了土压平衡盾构机在砂土地层中施工的主要问题和常见的几种盾构施工渣土改良方法,并以福州地铁2号线桔洪区间土体为试验土样,对比分析了膨润土、高分子材料和聚合物等改性助剂对砂土的改良效果,为指导富水砂层盾构渣土改良提供了有力依据。

In the course of shield construction, it is usually required that the soil in the range of the cutter plate has some characteristics of flow plasticity and low permeability, but it often does not have this characteristic in the actualconstruction. Therefore, it is necessary to improve the range of the cutter disk. Based on the working principle of earthpressure balance shield machine, this paper analyzes the main problems in the construction of earth pressure balanceshield machine in sand soil layer, and several common methods for improving the residual soil of shield construction.The improvement effect of bentonite, polymer material and polymer on the soil was compared with the soil samplesbetween the Fuzhou Metro Line 2. It provides a strong basis for guiding the improvement of shield soil in water rich sand layer.