盾构施工工艺诱发地表沉降规律浅析

Analysis of ground settlement induced by workmanship of shield tunnelling

在研究盾构施工工艺诱发地层沉降规律时,对施工工艺变化引起地表沉降的量化分析成果相对较少。将盾构工艺分为注浆填充率β、支护压力比λ和偏心率κ等3个主要因素,将其引入到Rowe等人提出的"间隙参数"的公式中,利用Loganathan等人提出的地表沉降预测解析公式,对上述3个工艺参数的变化对地表沉降的影响进行量化分析;同时以间隙参数为前提,对前人提出的等代层厚度参数取值进一步探讨,为复杂的盾构施工工艺的数值模拟提供计算依据。通过对西安地铁2号线试验段地表沉降实测资料进行反演,分析结果认为,提出来的间隙参数计算方法及修正等代层模型能较为真实地反应施工工艺水平,能够为盾构施工地面沉降控制提供一定的参考。

The researches on the quantitative analysis of ground settlement induced by the shield tunnelling workmanship are relatively less. In this paper, three workmanship parameters, i.e. grouting filling ratio, shield pitch ratio and support pressure ratio, are introduced into the gap parameters to make the quantitative analysis of ground settlement based on Loganathan expressions. The deep discussion about the equivalent circle zone which was proposed by some scholars is made to provide the basis of numerical analysis for the shield tunneling project. The back analysis of the Xi＇an metro line-2 is carried out to validate the rationality of the method introduced in this paper. It is shown that the method can factually reflect the workmanship level and offer a certain reference to the control of the ground settlement during the shield tunneling.