某隧道开挖过程中围岩稳定性数值模拟

发布时间：2018-08-02 17:26

【摘要】：本文基于宁夏民族自治区周潭市在建的炸山嘴隧道YK25+330～YK25+360段电到围岩大变形的情况,及连断(?)开挖过程存在有渗水,为了防止后续工程出现类似情况,特选取YK25+250～YK25+280段及YK25+330～YK25+360段两处断(?),利用ABAQUS建立模型从围岩稳定性及渗流入手进行计算分析,重点探讨了炸山嘴隧道开挖过种中围岩的应力,应变的变化情况及孔(?)水压力分布规律,并讨论这些规律对隧道稳定性的影响。1)隧道的周边位移不仅和初始应力场、围岩本身的强度参数c、φ值及隧道结构尺寸有关联,同时也与支护结构构(支护阻力)有关系,支护阻力增大时,围岩罡性位移移公减小,反之,技护阻力减小时,围岩围性位移将会增大,甚至失稳。2)选取YK25+250断雨和YK25+330断面.利用ABAQUS在合理的参数条件下建立二(?)模型计算发现,在该地质条件下(?)顶沉降随着初支厚度、混凝土强度、锚杆长度的增大西减小，，但影响到一定的值后,再增大对拱顶的影响可以忽略了。3)选择断面YK25+250～YK25+280和YK2+330～YK25+360在ABAQUS上建立三维模型.通过计算得到隧道开挖过程中周边围岩的应力应变及周围孔散水压力变化情况, YK25+250～YK25+280段最大应力出现在两边墙处,随着应力的增大,两边边墙处水平位移增大,孔隙水压力降至最小后围岩应力值增长速率减小。YK25+330～YK25+360段最大应力出现在拱顶处,随着应力增大.拱顶木平位移增大。孔隙水压力的变化也直接影响着应力的变化。4)现场监测开挖段过程中地表位移、拱顶沉降、围岩周边收敛变形并对监测数据进行统计分析,找到隧道开挖过程中隧道围岩的变化规律，并与数值模型计算所整理的数据进行外比.规定模型计算的正确性和合理性,以该结果为依据指导后续的工程设计施工。
[Abstract]:This paper is based on the large deformation of surrounding rock in YK25 330~YK25 360 section of Feshanzui Tunnel under construction in Zhoutan City, Ningxia National Autonomous region, and its continuous fault (?) There is water seepage in the excavation process. In order to prevent the similar situation in the subsequent projects, two fault sections (?) of YK25 250~YK25 280 and YK25 330~YK25 360 are selected, and the ABAQUS model is used to calculate and analyze the stability and seepage of surrounding rock. The stress and strain of surrounding rock in excavation of Feshanzui tunnel and the hole (?) The distribution of water pressure, and the influence of these laws on tunnel stability. 1) the surrounding displacement of the tunnel is not only related to the initial stress field, but also to the strength parameters c, 蠁 of the surrounding rock and the size of the tunnel structure. At the same time, it is also related to the structure of support structure (support resistance). When the support resistance increases, the displacement of the surrounding rock decreases, whereas, when the resistance is reduced, the surrounding displacement of surrounding rock will increase or even lose stability. 2) choose YK25 250 rain break and YK25 330 section. Using ABAQUS to establish two (?) The model calculation shows that, under the geological conditions, (?) With the thickness of initial support, the strength of concrete and the length of anchor rod decrease west, but the influence of increase on arch roof can be neglected after affecting a certain value. 3. 3) selecting section YK25 250~YK25 280 and YK2 330~YK25 360 to build 3D model on ABAQUS. The stress and strain of surrounding rock and the pressure variation of surrounding hole in tunnel excavation are obtained by calculation. The maximum stress of YK25 250~YK25 280 appears at both sides of wall, and with the increase of stress, the horizontal displacement of side wall increases with the increase of stress. When the pore water pressure decreases to the minimum, the growth rate of surrounding rock stress value decreases. YK25 330~YK25 360 maximum stress appears at the arch top and increases with the increase of the stress. The horizontal displacement of the arch is increased. The change of pore water pressure also directly affects the change of stress (.4) monitoring the surface displacement, the settlement of arch roof, the convergent deformation of surrounding rock and the statistical analysis of monitoring data during the excavation process. The variation law of surrounding rock during tunnel excavation is found and compared with the data collected by numerical model calculation. The correctness and rationality of the model calculation are stipulated, and the following engineering design and construction are guided by the result.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

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