软弱黄土隧道隧底受力变形特征与沉降控制研究
发布时间：2019-04-24 18:11
【摘要】：软弱黄土隧道的隧底受力变形一直是学术界和工程界较为关注的问题。由于黄土工程性质的特殊性，黄土隧道的隧底受力变形特征也与山岭隧道有很大的不同。为了明确软弱黄土隧道的隧底受力变形特征，以便提出有效的沉降控制措施，本文以大有山黄土隧道工程为研究对象，结合数值模拟、现场实测等手段对软弱黄土隧道的隧底围岩应力分布及变形、隧道基底加固以及隧底沉降变形控制等进行分析研究，得到如下主要结论： 1、对黄土隧道两种工况下的台阶法施工过程进行模拟，并结合现场实测数据对隧底围岩的应力分布及变形规律进行分析。结果表明，仰拱区域围岩应力分布不均匀，在边墙与仰拱的交角处应力较大，仰拱中心应力则较小，隧底隆起较为明显。在雨水的影响下，隧底土体应力减小，塑性区及变形明显增大。 2、对软弱黄土隧道基底加固常用的处理措施进行了对比分析，得出高压旋喷桩具有施工占地少、振动小、加固质量有保证等优点，适用于大有山黄土隧道的基底加固中。 3、对高压旋喷桩加固后的复合地基进行模拟分析，研究隧底黄土变形受力特征，得出地基处理后隧道周边收敛主要位于边墙部位，，隧底隆起量相比地基处理之前大幅减小，塑性区主要分布于隧道上部未加固的黄土地层中。 4、对施工完成后的工后沉降进行了模拟，并与现场监测结果进行了对比分析。结果表明，隧道沉降变形主要发生在仰拱回填完成后的12天以内，随后变形速率逐渐减小，在36天时沉降变形基本趋于稳定。
[Abstract]:The stress and deformation of soft loess tunnel bottom has always been concerned by the academic and engineering circles. Because of the particularity of loess engineering, the stress and deformation characteristics of loess tunnel bottom are very different from mountain tunnel. In order to clarify the characteristics of stress and deformation at the bottom of soft loess tunnel in order to put forward effective settlement control measures, this paper takes Dayou Shan loess tunnel project as the research object, combined with numerical simulation, The stress distribution and deformation of surrounding rock of soft loess tunnel, the reinforcement of tunnel base and the control of settlement and deformation of tunnel bottom are analyzed and studied by means of field measurement and other methods. The main conclusions are as follows: 1, In this paper, the construction process of loess tunnel by step method under two working conditions is simulated, and the stress distribution and deformation law of surrounding rock at the bottom of the tunnel are analyzed in combination with the field measured data. The results show that the stress distribution of surrounding rock in the inverted arch region is not uniform, the stress at the corner between the side wall and the inverted arch is larger, the central stress of the inverted arch is smaller, and the uplift of the tunnel bottom is more obvious. Under the influence of Rain Water, the stress of tunnel bottom soil decreases, the plastic zone and deformation increase obviously. 2. The common treatment measures for foundation reinforcement of soft loess tunnel are compared and analyzed. It is concluded that high-pressure rotary jet pile has the advantages of small construction area, small vibration and guaranteed reinforcement quality, which is suitable for the foundation reinforcement of Dayoushan loess tunnel. 3, the composite foundation strengthened by high-pressure rotary jet pile is simulated and analyzed, and the deformation and stress characteristics of loess in tunnel bottom are studied. It is concluded that the convergence of tunnel periphery after foundation treatment is mainly located in the side wall, and the uplift of tunnel bottom is much less than that before foundation treatment. The plastic zone is mainly distributed in the unreinforced loess strata in the upper part of the tunnel. 4. The post-construction settlement after construction is simulated and compared with the results of on-the-spot monitoring. The results show that the settlement of the tunnel mainly occurs within 12 days after the backfilling of the inverted arch, and then the deformation rate decreases gradually, and the settlement tends to be stable at 36 days.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2
本文编号：2464669
[Abstract]:The stress and deformation of soft loess tunnel bottom has always been concerned by the academic and engineering circles. Because of the particularity of loess engineering, the stress and deformation characteristics of loess tunnel bottom are very different from mountain tunnel. In order to clarify the characteristics of stress and deformation at the bottom of soft loess tunnel in order to put forward effective settlement control measures, this paper takes Dayou Shan loess tunnel project as the research object, combined with numerical simulation, The stress distribution and deformation of surrounding rock of soft loess tunnel, the reinforcement of tunnel base and the control of settlement and deformation of tunnel bottom are analyzed and studied by means of field measurement and other methods. The main conclusions are as follows: 1, In this paper, the construction process of loess tunnel by step method under two working conditions is simulated, and the stress distribution and deformation law of surrounding rock at the bottom of the tunnel are analyzed in combination with the field measured data. The results show that the stress distribution of surrounding rock in the inverted arch region is not uniform, the stress at the corner between the side wall and the inverted arch is larger, the central stress of the inverted arch is smaller, and the uplift of the tunnel bottom is more obvious. Under the influence of Rain Water, the stress of tunnel bottom soil decreases, the plastic zone and deformation increase obviously. 2. The common treatment measures for foundation reinforcement of soft loess tunnel are compared and analyzed. It is concluded that high-pressure rotary jet pile has the advantages of small construction area, small vibration and guaranteed reinforcement quality, which is suitable for the foundation reinforcement of Dayoushan loess tunnel. 3, the composite foundation strengthened by high-pressure rotary jet pile is simulated and analyzed, and the deformation and stress characteristics of loess in tunnel bottom are studied. It is concluded that the convergence of tunnel periphery after foundation treatment is mainly located in the side wall, and the uplift of tunnel bottom is much less than that before foundation treatment. The plastic zone is mainly distributed in the unreinforced loess strata in the upper part of the tunnel. 4. The post-construction settlement after construction is simulated and compared with the results of on-the-spot monitoring. The results show that the settlement of the tunnel mainly occurs within 12 days after the backfilling of the inverted arch, and then the deformation rate decreases gradually, and the settlement tends to be stable at 36 days.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2
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