土压平衡盾构土仓排土引起的干砂地层响应特征分析

发布时间：2018-02-26 15:06

本文关键词： 无水砂层土压平衡盾构排土地层响应离散元　出处：《郑州大学学报(工学版)》2017年01期 　论文类型：期刊论文

【摘要】：为阐明土压平衡盾构挤土与排土掘进状态对周围土体的扰动机理,采用离散元方法建立土仓不排土与排土两组盾构掘进二维数值模型,比较分析了两种工况下盾构掘进时掌子面及周围地层的细观力学变化特征.研究表明:不排土工况下,盾构对周围土层有明显挤密,土体竖向位移呈椭圆形、水平位移呈圆形向前方扩散变小;排土工况下,刀盘周围土体无明显挤密,水平位移很小,竖向位移呈不规则漏斗状向地表延伸变大.不排土对周围土体应力影响大,掌子面水平应力分布均匀;排土工况下盾构前方土体应力与初始地层接近,土仓的排土,使掌子面水平应力的分布变化较大.
[Abstract]:In order to elucidate the disturbance mechanism of earth pressure balance shield tunneling state to surrounding soil mass, the discrete element method is used to establish two groups of two-dimensional numerical models for shield tunneling. In this paper, the characteristics of mesomechanical changes of the face of the shield and the surrounding strata during shield tunneling are compared and analyzed. The results show that the shield tunneling has obvious compaction to the surrounding soil layer and the vertical displacement of soil is elliptical under the condition of no soil displacement. The horizontal displacement becomes smaller in circular direction, the soil around the cutter head is not compacted obviously, the horizontal displacement is very small, and the vertical displacement extends to the ground in an irregular funnel-shaped manner, which has a great influence on the stress of the surrounding soil. The distribution of horizontal stress on palm plane is uniform, and the stress of soil in front of shield is close to the initial stratum under the condition of draining earth, which makes the distribution of horizontal stress of palm surface change greatly.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金青年资助项目(51208516) 中南大学研究生创新项目(2016zzts414)
【分类号】：U455.43

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