【作者】 陈波；

【导师】 范秋雁；

【作者基本信息】 广西大学 ， 岩土工程， 2004， 硕士

【摘要】 本文通过大型室内模拟试验，研究考虑施工过程的基坑锚杆支护。模拟试验首先建立了一个均质的土质基坑，然后进行基坑开挖和锚杆支护施工。通过对试验数据进行整理分析，得出了在基坑开挖、钻孔、锚杆的加入、灌浆、预应力的施加等施工过程中，土中应力状态的变化规律、锚固段应力的变化规律以及基坑壁侧向位移的变化规律：①基坑刚开挖卸荷时，基坑壁附近的土体应力状态明显发生变化，变化趋势大体上都是减小的；②土层锚杆锚固段应力是非均匀分布的，是按一定规律递减的；③锚杆刚施加时受力较小，只有当基坑开挖下一步后，锚杆的受力才会增加；④基坑侧向位移随着施工过程的进行，呈现增大的变化趋势，曲线大体上呈抛物线状。 在模拟试验的基础上，对土层锚杆的锚固机理和变形机理进行了探讨，结论为：基坑周围的土体、钢筋、灌浆体以及锚杆承台(还可以包括挂网和喷浆)是一个受力的整体，必须用完整的力学模型完整地求解，同时，不仅要考虑这一完整的力学系统，还要考虑完整的受力过程，也即在进行力学分析时必须考虑基坑的开挖过程及锚杆的打入过程，这样，才能较为完整地并精确地计算出基坑锚杆支护后锚固体的变形量。更多还原

【Abstract】 The paper researches on bolt supporting of foundation pit considering construction process, through large-scale indoor stimulation test. A homogeneous soil foundation pit is set up firstly in the stimulation test; then excavating the foundation pit and bolt supporting construction is done. Through analyzing and arranging the test data, the paper attained change rules of soil stress state and anchoring segment stress and foundation pit side displacement in considering construction process, such as excavating the pit, drilling, grouting, forcing beforehand stress etc.. (1) When the foundation pit is excavated and unloaded, the soil stress state near the foundation pit wall changes obviously. The variation tendency is all reduced on the whole. (2) The cut stress of soil bolt anchoring segment is asymmetry distributing and decreases progressively according to certain rule. (3)The force of bolt is smaller ,no other than after the foundation pit excavating continues next step, the force of bolt will increase. (4)The side displacement of foundation pit presents the variation tendency increased with going on of construction process, the curve takes on the form of parabola on the whole.On the basis of stimulation test, it probes soil bolt anchoring and deformation mechanism. The conclusion is: The soil body around the foundation pit, steel bar, grouting body and rider cap of bolt is a forced whole(it still may include hanging net and shotcrete),it must be answered integrality on using whole mechanics model. It not only considers the whole mechanics system, but also considers whole forced process. Namely when carrying through mechanics analysis, the excavating process of foundation pit and joined process of bolt must be considered. In this way, the deformation of anchoring body can be calculated more integrality and accurately after foundation bolt supporting.更多还原