摘要
盾构法是城市地铁隧道施工的主要工法之一。盾构推进过程中不可避免地引起掌子面土体扰动,进而对盾构前方土体的稳定性产生较大影响,而目前对于盾构推进引起前方土体的位移与应力的研究较少。利用Mindlin解,基于盾构受力特点建立力学模型,推导掌子面前方地层变形与应力计算公式,并将工程实测值与理论计算值进行对比分析,得出盾构推进引起土体位移和应力的影响范围及影响程度。结果表明,掌子面前方土体变形主要受盾壳与土体之间的摩擦力影响,正面推力附加应力引起的变形较小,盾构推进对前方土体的应力主要由摩擦力引起。研究结果可为盾构现场施工控制提供理论和计算依据。
Shield tunneling method has become one of the main construction methods of urban underground tunnels. However,the soil ahead of the shield cutterhead is disturbed during shield tunneling, thereby influencing the stability of the ground ahead of the cutterhead. However, few studies have focused on soil deformation and stress characteristics ahead of the cutterhead. In this paper, a mechanical model of shield driving was established and the formula of soil deformation and stress ahead of the cutterhead was deduced, based on Mindlin solution and the shield construction characteristics.Meanwhile, the degree of soil deformation and stress was obtained based on analysis of the field test data and theoretical calculations as well as the influence range. The result showed that the soil deformation was mainly influenced by the frictional force between the shield and ground and was less affected by frontal subsidiary stress. Furthermore, the soil stress ahead of the cutterhead was mainly influenced by frictional force. Therefore, the results can provide theoretical basis for shield construction control.
引文
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