【作者】 刘竞；

【导师】 杨小礼； 盛宴；

【作者基本信息】 中南大学 ， 土木工程， 2023， 硕士

【摘要】 隧道掌子面稳定性受到多种因素的影响,如地震、地下水位、支护方式等。其中,地震作用是一种常见的外部扰动力,它会引起荷载增加,从而降低掌子面稳定性。此外,渗流的存在也会会大大降低隧道掌子面的稳定性。本文主要研究内容如下:(1)引入抗拉强度截断对M-C准则进行了修改,允许在抗拉条件下土体的非线性强度降低,并对掌子面受地震影响进行了拟动力分析。采用拟动力法模拟加速度随时间和空间变化的地震波,提高了模拟的准确性。在极限分析框架下,得到掌子面支护压力的表达式,并采用穷举法得到了最不利状态下掌子面支护压力。(2)针对渗流条件下的隧道掌子面提出了玻纤锚杆加固的计算方法。构建了满足上限定理的破坏模式,根据水头的经验分布公式,在能量计算中加入了孔隙水压力。通过使用有限厚度的相互作用区域来模拟土壤和玻纤锚杆之间的相互作用。给出了相应的计算公式和结果图表。(3)对于含有多土层的情况,土层的存在会对掌子面产生不利影响。利用离散化技术在三维空间中构建分层土的三维掌子面破坏模型。限制了掌子面所在地层的角度、高度和厚度。考虑地震波的空间和时间特征,对掌子面进行了拟动力分析。图41幅,表6个,参考文献100篇更多还原

【Abstract】 The stability of the tunnel face is affected by various factors,such as earthquake,groundwater level,and support method.Among them,seismic action is a common external disturbance force,it will cause load increase,thus reducing the stability of the tunnel face.In addition,the presence of seepage can also greatly reduce the stability of the tunnel palm face.The main research elements of this thesis are as follows:(1)The tensile strength truncation was introduced to modify the M-C criterion to allow for a reduction in the nonlinear strength of the soil under tensile conditions,and a proposed dynamic analysis of the tunnel face subjected to seismic effects was carried out.The simulated dynamic method was used to simulate the seismic waves with acceleration varying in time and space,which improved the accuracy of the simulation.In the framework of limit analysis,the expression of tunnel face support pressure is obtained,and the support pressure of tunnel face under the most unfavorable condition is obtained by using the exhaustive method.(2)The calculation method of bolt reinforcement is proposed for the tunnel face under seepage conditions.A damage model satisfying the upper limit theorem is constructed,and the pore water pressure is added to the energy calculation according to the empirical distribution equation of water head.The interaction between the soil and the bolt is simulated by using an interaction zone of finite thickness.The corresponding calculation equations and graphs of the results are given.(3)For the case containing multiple soil layers,the presence of soil layers can adversely affect the palm face.A three-dimensional tunnel face damage model with layered soils is constructed in three-dimensional space using discretization techniques.The angle,height and thickness of the layer where the tunnel face is located are restricted.Considering the spatial and temporal characteristics of seismic waves,the proposed dynamic analysis of the tunnel face is carried out.更多还原