超欠挖状态下支护结构的力学特性研究

发布时间：2018-06-02 15:33

本文选题：不规则围岩表面 + 厚壁圆筒理论　；参考：《煤炭学报》2017年11期

【摘要】：在传统的喷射混凝土支护结构设计中,通常假设支护结构层是一个薄壁等厚层。钻爆法开挖的隧道围岩表面由于受爆破的影响存在不同程度的超欠挖,导致初期支护喷射混凝土结构层厚度不均匀。充分考虑超欠挖情况下隧道围岩表面的不平整性,根据喷射混凝土支护厚度将支护后的隧道表面不规则形状依据实际喷层情况归结为未完全填充、局部填充和完全填充三类。基于弹性力学厚壁圆筒理论,建立了单一喷射混凝土支护结构和喷射混凝土+钢格栅联合支护结构的等效刚度与最大支护力的理论公式。基于上述原理,结合收敛-约束法对某隧道开挖工程的稳定性进行了分析,得到了隧道支护结构的安全系数。结果表明,所提出的方法对超欠挖隧道的稳定性分析具有较好的适用性,验证了该方法的可行性。
[Abstract]:In the traditional design of shotcrete support structure, it is usually assumed that the support structure layer is a thin wall and equal thickness layer. Due to the influence of blasting on the surrounding rock surface of the tunnel excavated by drilling and blasting method, there are some degrees of overdigging, which leads to the uneven thickness of the initial support shotcrete structure layer. According to the thickness of shotcrete support, the irregular shape of tunnel surface after support is classified into three types: incomplete filling, local filling and complete filling according to the actual spray layer. Based on the theory of thick wall cylinder in elastic mechanics, the equivalent stiffness and maximum support force of single shotcrete support structure and shotcrete steel grille combined support structure are established. Based on the above principle, the stability of a tunnel excavation project is analyzed by combining the convergence-constraint method, and the safety factor of the tunnel supporting structure is obtained. The results show that the proposed method is applicable to the stability analysis of over-underexcavated tunnels, and the feasibility of the method is verified.
【作者单位】：山东大学岩土与结构工程研究中心;
【基金】：国家自然科学基金面上资助项目(51379113) 国家重点研发计划资助项目(2016YFC0600803)
【分类号】：TD353

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