【作者】 王志达；

【导师】 龚晓南；

【作者基本信息】 浙江大学 ， 岩土工程， 2009， 博士

【摘要】 修建人行地下通道是缓解城市交通拥挤、保障行人交通安全、提高城市运行效率的一项有效措施。人行地道施工不可避免对周边环境造成不利的影响,严重者可能影响地面建构筑物和地下管线的正常使用。因此,选择合适的施工方法减小其环境效应具有非常重要的工程意义。本文在前人研究成果的基础上结合实际情况对城市人行地下通道施工技术及其环境效应进行了较系统的研究,主要工作和研究成果如下:1.基于Pasternak双参数模型建立了接近工程实际的管棚工作机理力学模型和微分控制方程并求解。2.基于普氏平衡拱理论和Terzaghi松散介质理论提出均质土层中城市人行地道采用全断面开挖时开挖进尺的计算方法,将该法推广应用到常用开挖方法(台阶法、CRD法)和成层土中,通过工程实例验证表明这两种计算方法可以应用到设计施工中。3.对砂质粉土和淤泥软土中人行地下通道埋深4m时的施工技术进行了详细的数值模拟和分析,对埋深变化时(埋深2～7m)砂质粉土中开挖参数(开挖进尺和分部开挖长度)进行数值模拟分析。在保证结构和周边环境安全的前提下,对砂质粉土和淤泥软土中修建人行地下通道施工工艺(包括开挖方法、开挖进尺、分部开挖长度、格栅钢架间距、支护滞后长度等)给出合理的建议。4.对均质土中单井和多井降水引起的孔隙压力和地表沉降变化应用数值模拟进行详细研究,在研究结果基础上建立了砂质粉土中人行地道的降水模型,研究不同降水方法引起的孔隙压力及地表沉降变化,指出边开挖边降水是适合人行地道的降水方法。5.对不同土层、不同施工工艺、不同埋深等因素对地表沉降的影响进行了数值模拟和分析,在研究结果基础上总结了人行地道开挖引起地表沉降的影响因素和控制措施。6.对不同条件下(不同材质、不同埋深、不同间距)人行地道施工对地下管线的影响进行数值模拟和分析。7.通过对一个实际工程的数值模拟结果与实测值的对比,验证了本文提出的施工工艺可以应用到实际工程中。更多还原

【Abstract】 Construction of the underpass is an effective measure to ease city traffic congestion, enhance pedestrian safety and improve the efficiency of the city. The influence of the underpass construction to the surrounding environment is inevitable, even may affect the ground buildings and the normal use of the underground pipeline. Therefore, it is significant to select an appropriate construction method to reduce the environmental effects. This paper, on the basis of the results of previous studies, has done a systematic study on the actual situation of the city underpass construction technique and its environmental effects. It runs as follows.1. Based on two-parameter Pasternak model, a calculation model and differential governing equation which reflects the work of pipe roof mechanism has been set up and solved.2. Based on M. M. Protodyakonov Equilibrium Arch Theory and Terzaghi Loose medium Theory, a calculating method of digging length has been given when full-face tunnel excavation is adopted in shallow tunnel construction in homogenized soil. Then, the methods have been applied to usual excavation method (e.g. step method, CRD method) and the construction in layered soil. At last, the methods have been proved to be practical in design and construction according to application in an example.3. A detailed analysis of the numerical simulation of the underpass, 4m depth in silty sand soil and soft soil, construction technology has been conducted. Then, numerical analysis of digging length and division excavation length has been carried out according to different digging length (2～7m). On the premise of the safety of underpass and surrounding environments, reasonable proposals have been given to underpass construction technology when it is done at different depths of silty sand soil and soft soil (including excavation methods, digging length, division excavation length, steel grating spacing, the length of support etc.).4. Through numerical simulation, detailed study has been done to the pore pressure changes and changes in surface subsidence caused by single-well and multi-well precipitation in homogeneous soil. On the basis of the results, a precipitation model of the underpass construction in gouache-rich sand soil has been made. Pore pressure changes and changes in surface subsidence caused by different precipitation construction technology have been studied to point out that dynamical precipitation is an appropriate precipitation method.5. Numerical simulation and analysis on the impact of the different soil, construction technique and depth to surface subsidence have been done. On the basis of research results influencing factors and control measures have been summarized.6. Numerical simulation and analysis on the impact of the underpass construction to underground pipeline under different conditions (including different material, depth and space) has been done.7. Through the study of an actual subject and the comparison between the numerical simulation results and actual data, the construction methods proposed by this paper have been proved and can be applied to practical engineering.更多还原