深圳地铁一期工程浅埋暗挖施工地层变形模式

基于城市地下工程浅埋暗挖法施工的地层变形特点，提出了地层整体下沉和抽冒式地层变形的模式，分别建立了相应的力学模型，给出了相应地层变形模式下的稳定性特点和地层沉降曲线，并对其主要影响因素进行了分析。该模型可以较好地解释不同地层的变形特点和规律，分别揭示了黏性土和砂性土地层条件下产生大变形及地面坍塌的机理，指出地层变形通常是由结构层的失稳和破坏所致，并且在整体沉降模式下结构层表现为梁式结构，而抽冒型变形模式下结构层则表现为压力拱结构，因此，梁/拱结构的稳定性是地表沉降控制的核心。梁式结构层控制的重点是梁端支承点的加固和离层区域的及时补充注浆，而拱式结构控制的重点则是拱角地层的稳定性。由此可为地层变形的控制和环境评价标准的制定提供依据。结合深圳地铁一期工程6标段和3A标段的典型条件，分别针对整体沉降和抽冒结构模式成功地进行了地层变形控制实践，取得了理想的效果。同时也为深圳地铁及城市地下工程施工地层控制标准的制定提供了有益的建议。该成果对城市地下工程的环境控制具有普遍的指导意义和借鉴作用。

Strata deformation pattern of first-stage construction in Shenzhen Subway using shallow tunnel construction method

This paper gives integral strata deformation pattern and slumping arch strata deformation pattern based on the strata deformation characteristics in urban subway using shallow tunnel construction method. Mechanical models, stability features, major influencing factors and settlement curves of strata are also given，which can perfectly explain the characteristics and patterns of strata deformation, and reveal the mechanics of large deformation and surface subsidence in clay soil and sandy soil. It is shown that strata deformation is usually caused by the destabilization and destruction of structure strata. The strata structures act as beam in integral settlement pattern, while pressure arch in slumping arch deformation pattern. Thereby the beam or arch stabilization is the core of ground settlement control; and respectively the emphases are strengthening beam bearing point and in-time complementally grouting in bed separation region, as well as controlling the stability of arch springing strata. With the merits of these models we can offer strata deformation control standards and environmental evaluation criterion. Based on the typical project of sector 6 and sector 3A of the first-stage subway construction in Shenzhen, good result is achieved successfully in strata deformation control of both patterns; meanwhile available suggestion is proposed on the strata deformation control standard of Shenzhen Subway as well as other urban underground works. The achievement of this paper will be the prevalent guidance to environmental control in urban underground engineering.