【作者】 黄烨；

【导师】 黄明利；

【作者基本信息】 北京交通大学 ， 地下工程， 2009， 硕士

【摘要】 随着我国国民经济的迅速发展,城市人口规模不断扩大,为缓解交通压力,大量的城市隧道需要修建。由于城市空间资源紧张,周边环境复杂,对城市小净距隧道施工过程中如何控制对环境的影响提出了较高要求。其中主要有下穿建筑物过程中对建筑物沉降的控制、爆破振动对衬砌结构以及地表建筑物影响的控制。本文研究背景为厦门机场路JC3标隧道,该隧道为浅埋大跨小净距隧道,下穿密集建筑群,地质条件复杂,存在建筑物沉降控制、爆破振动控制等众多施工难点,是典型的城市小净距隧道。依托于该隧道工程,利用理论分析、数值模拟和现场监测等相结合的方法,对城市小净距隧道施工过程中的建筑物沉降控制和爆破振动控制做了系统的研究,主要有:(1)总结分析了建筑物沉降的主要因素及控制技术,对常用的几种控制措施进行了数值模拟分析,对比了各自的控制效果,为方案的选择提供参考。由于隧道开挖是一个动态的过程,提出在静态控制措施基础上进行跟踪注浆,动态地控制建筑物的沉降,并分析了注浆抬升的机理及特点。(2)通过厦门机场路JC3标隧道下穿建筑物的工程实践,总结了建筑物沉降措施的主要施工方法。认为在建筑物下进行注浆管棚和全断面注浆对建筑物沉降控制效果较好。合理的施工步序调整有利于控制建筑物的差异沉降。通过实践对比及监测分析,动态跟踪注浆具有良好的控制效果,其中地表跟踪注浆比洞内跟踪注浆效果更显著,提出在对沉降控制严格且有场地条件的情况下尽量采用地表跟踪注浆,并分析了实现动态注浆有效稳定抬升的基本条件。(3)通过数值模拟研究了城市小净距隧道施工过程中后行洞爆破对先行洞衬砌结构的影响。二维计算中研究了先行洞不同支护状态、后行洞不同开挖方式以及不同净距各种工况条件下爆破振动对衬砌结构的影响。三维计算中分析了爆破振动对衬砌结构在纵向范围内的影响,并提出了二次衬砌浇筑的合理时机。(4)总结文献资料,分析了爆破振动对结构物的影响。利用现场监测,数据回归了爆破振动在该地层条件下的传播规律,为爆破方案设计提供参考。根据现场埋深逐渐变小的情况,为保证地表建筑物的安全,对原有爆破参数进行了优化,成功将爆破振动控制在1cm/s以下。更多还原

【Abstract】 With the rapid development of national economy and gradual increasing of the urban population, a large number of urban tunnels need to be built in order to alleviate the traffic pressure. It proposes high requirements on neighbor tunnels about how to control environmental impact during the construction process for urban space resource is limited and surrounding environment is very complicated. Therefore, we should control the settlement of the building when one tunnel is excavating under the building and vibration of the linings caused by blasting. The research background in this paper is Wucunshan tunnel on JC3 bid section of airport Highway in Xiamen. As a shallow-depth large-scale neighbor tunnel, Wucunshan tunnel locates in complex geological condition and goes through dense buildings, and has much difficulty in construction including building settlement control and blasting vibration control. Based on Wucunshan tunnel, building settlement control and blasting vibration control during the construction process of urban neighbor tunnel was systematically studied by theoretical analysis, numerical simulation and in-situ measurement, and some inclusions were obtained as following:(1)This paper analyzed and summarized the key factors of building settlement and control technology. Several common control measures were numerically simulated and comprised, which could provide reference for choosing good scheme. As the tunnel excavation is a dynamic process, dynamic tracking grouting is proposed based on static control measures, and the mechanism and characteristic of grouting uplift is analyzed.(2) The project practice of Wucunshan tunnel indicates that grouted roof pipe and full face grouting has a better control effect to the settlement of the building and reasonable construction sequence is conducive to control the differential settlement of the building. And comparative analysis of practice and monitoring shows that the dynamic tracking grouting is a good control method, in particular, surface tracking grouting is better than inside tracking grouting. Therefore, this paper suggests adopting surface tracking grouting as far as possible if the settlement should be strictly controlled and there is enough ground for surface tracking grouting, and analyzes basic conditions which should be satisfied in order to achieve effective uplift.(3)The effect of the later hole’s blasting on the first hole was numerically simulated in urban neighbor tunnel. Two-dimensional simulation studied different effect of blasting vibration on lining when different support state of the first hole, different excavation method of the back hole and different distance of two holes. Three-dimensional simulation analyzed the longitudinal effect of blasting vibration on lining, and suggested reasonable time to pour secondary lining.(4) According to historical documents, the paper analyzed and summed up the detailed effect of blasting vibration on the structure. The spread formation of blasting vibration in the stratum was regressed based on monitoring data, which can provide reference for blasting scheme. In order to ensure the safety of the surface buildings, the original blasting parameters were optimized now that the depth is gradually decreasing, as a result, the blasting vibration rate was successfully controlled below 1 cm / s.更多还原