中文摘要：

本文以在建的莞惠城际轨道交通项目为依托,利用现场试验、数值模拟和室内模型试验等手段对穿越砂土地层的浅埋暗挖隧道预加固技术进行研究,通过控制围岩-支护体系的变形,分析适宜的预加固方法、范围和参数,结论如下：洞内帷幕注浆和地表注浆均难以形成止水帷幕,选择洞内水平旋喷桩配合掌子面注浆作为穿越砂土地层的最优预加固方案;依靠增加注浆范围控制砂土地层中的拱顶沉降和水平收敛是不利的,但可加强非砂土地层的围岩整体性,对控制地表沉降也较为有利;改变加固区参数对控制砂土地层中隧道拱顶的沉降有较大帮助,注浆效果越好,围岩的自承载能力提高越大,而其水平位移几乎没有变化。

英文摘要：

This article is based on the project of Guan-Hui inter-city rail transit. It uses field experiment, laboratory model experiments and numerical simulation method and develops a pre-reinforced technology for shallow excavation tunnel crossing sand ground. In analysis of the deformation of surrounding rock and supporting system suitable pre-reinforced method, scope and parameters can be obtained. The conclusions are as follows Curtain grouting in tunnel and surface grouting are difficult to form waterproof curtain. When crossing sand strata, horizontal jet grouting and tunnel face grouting are the best pre-reinforcement scheme. Increasing grouting range is disadvantageous to control vault subsidence and horizontal convergence in sand strata, but can strengthen the integrity of the surrounding rock in unsand strata. Meanwhile, it is favourable to control the subsidence of ground. Changing the reinforced area parameter is highly advantageous to control the settlement of tunnel vault in sand strata. The better grouting quality accomplished, the greater the self-supporting capability of surrounding rock improved, while the horizontal displacement is nearly unchanged.