【作者】 梁精华；

【导师】 朱伟；

【作者基本信息】 河海大学 ， 岩土工程， 2006， 硕士

【摘要】 盾构施工技术在我国重大地下工程的应用越来越广泛,已经成为了城市地下铁道建设的主要方法。使用盾构法施工时,对盾尾空隙进行壁后注浆是盾构施工的必备及关键工序,通过充填盾尾空隙以达到主动控制地层沉降及地层应力释放的目的,从而减少隧道周围地层位移和地表沉降。当前关于盾尾空隙壁后注浆的研究主要集中在数值分析方面,而其中对注浆参数的选取过分依赖于人为的经验和统计规律,对于壁后注浆体在硬化的过程中受注浆压力作用下的变形规律认识仍不明确。因此本文针对南水北调中线穿黄隧道盾构法施工中的细砂地层,进行了注浆材料的优化配比试验,并研制了浆体收缩试验装置和大型浆体压力消散试验模型对注浆后浆体在压力作用下的变形特性进行了试验研究。主要研究内容如下: (1) 针对南水北调中线穿黄隧道中细砂土质,采用均匀设计的试验方法,进行了壁后注浆材料的配合比优化试验研究,为工程上选取最适宜的浆液配比提供了基础。并探讨了注浆材料各组分对浆液性能的影响,研究结果表明膨润土和减水剂的掺量会显著影响浆液的各项性能。 (2) 研制了浆体体积收缩实验装置,比较系统地研究了浆液注入盾尾空隙后浆体的变形规律,探讨了注浆压力、注浆材料对注浆体变形规律的影响,提出了反映浆体变形规律的数学模型。 (3) 研制了大型壁后注浆单元模型实验设备,利用该设备进行了壁后注浆浆体压力消散试验,并对周围土体为粘土和砂土的浆体压力消散规律进行了对比分析,将试验结果与由浆体变形模型推算得到的压力变化规律相比较,证实了前面提出的浆体变形模型的可靠性。更多还原

【Abstract】 With the wide use of Shield tunneling method in important substructure works in our country, it has become a major method applied in city subway construction. During the construction with shield machine, backfill grouting is a necessary and key procedure, which can actively control stratum displacement and ground-stress release by filling the shield tail void, and thus reduce surround soil displacement and surface settlement. Current studies, however, focus mainly on the numerical simulation of backfill grouting and the deciding of parameters excessively relied on construction experience and statistical data, therefore it is still unclear about the deformation law of hardening grout under grouting pressure. This paper aimes for the fine sand medium during the construction of YellowRivercrossing tunnel with shield tunneling method, a series of grouting material optimal mixing proportion tests were carried out. With the developed grout shrinking test apparatus and large scale grouting pressure dissipation test appratus, the grout deformation properties under pressure were studied. The main works of this paper are as follow:(1) Aiming at the fine sand medium of YellowRivercrossing tunnel, uniform experimental method was applied in the optimal formula of grouting material, it makes basis for engineering suitable slurry preparation. The influences of grouting material additives on slurry properties were also analyzed. Test results show the content of bentonite and water reducing agent has significant influence on slurry properties.(2) Developed a set of grout shrinking test apparatus and use it systemly studied the grout deformation law after grouting. Discussed the influence of grouting pressure and grouting material on grout deformation. Based on the tests a mathematical model was proposed to simulate the deformation of grout.(3) Developed a large scale grouting pressure dissipation test apparatus and use it studied the grouting pressure dissipation properties. The grouting pressure dissipation law of surrounded each with clay and sand was comparatively analyzed. The test results fit well with the results calculated with the proposed grout deformation mathematical model, which confirmed the reliability of this model.更多还原