基于Peck公式的盾构隧道施工引起的地层三维沉降预测

盾构隧道施工会诱发地层沉降,合理地预测地层沉降对于保护邻近地下结构具有重要意义。首先,通过分析地表与地表以下深层土体的沉降规律,建立二者之间的联系;然后,基于Peck公式,通过引入不同种类土体的参数a,掌子面地表位移释放率η以及地表纵向沉降最大斜率k,提出不同种类土体中单、双洞盾构隧道施工诱发地层三维沉降的计算公式;最后,利用工程实测数据进行了对比验证,并对相关参数影响规律进行了简要分析。研究结果表明:本文方法与实测数据吻合良好,验证了该方法的准确性和适用性;合理的控制先、后行隧道开挖距离可以有效地减小掌子面土体沉降;地层沉降槽形态变化系数C(z)可以较好地预测双洞隧道开挖时任一深度土体沉降槽的形态。文末通过对大量实测数据分析,给出了相关参数的取值范围,可为无工程经验地区提供参考。

Prediction of three-dimensional subface and subsurface settlement caused by shield tunnelling based on Peck formula

The construction of urban shield tunnel will induce the ground settlement, and reasonable accurate prediction of the ground settlement is of great significance for the protection of adjacent structures. Firstly, based on the analysis of the settlement law of the surface and subsurface, the relationship between the two was established. Then, based on the Peck formula, by introducing the parameter a of different types of soil, the surface displacement release rate η of the palm surface, and the maximum slope of the vertical settlement of the ground surface k, the three-dimensional formation induced by single and double shield tunnels in different types of soil were proposed. Finally, the comparative analysis was made by using the measured data of the project, and the influence law of the relevant parameters was analyzed briefly. The research shows that the method in this paper is in good agreement with the measured data, which verifies the accuracy and applicability of the method. Reasonable control of the excavation distance of the first and the second tunnel can effectively reduce the soil settlement on the face of the tunnel. The coefficient C(z) can accurately predict the shape of settlement groove at any depth in double tunnels. At the end of the article, through analysis of a large number of measured data, the value range of relevant parameters is given, which can provide a reference for areas without engineering experience.