饱水土质隧洞变形特性分析及影响因素研究

发布时间：2018-05-03 19:51

本文选题：隧道工程 + 饱水土质隧洞　；参考：《岩石力学与工程学报》2014年S1期

【摘要】：基于新疆库尉引水隧洞现场监测资料,对饱水土质隧洞变形特性及影响因素进行深入分析。根据其主导影响因素将土质隧洞的变形分为3个阶段:横向空间效应影响阶段→纵向空间效应+时间效应影响阶段→时间效应阶段,横向空间效应影响为开挖时出现塌方、冒顶的主要因素,可通过超前支护、减小横向空间面积等方式降低其影响;纵向空间效应+时间效应主导着第二阶段的变形,其合理的分离可为参数反演提供依据;第三阶段的时间效应主要为流变变形。对不同埋深、围岩类型以及支护强度影响下监测的变形数据的分析可知:低液限粉(黏)土整体性较好,主要发生与埋深有较大关系的形变变形,埋深越大,变形越大,且具有一定的流变特性;粉土夹砂层和粉细砂夹砾石排水量大,开挖过程中易发生小范围塌方,其变形主要以洞周一定范围内的松动变形为主,且与夹砂层的位置有较大关系,埋深对其变形影响不显著,在采取强支护措施及分步开挖方式下,监测到的变形量值均较小。支护结构在拱顶和边墙部位的变形特性有很大差异:拱顶变形稳定时间短,变形量小;低液限粉(黏)土围岩边墙处围岩塑性区范围随埋深增大,应力释放时间效应明显,形变压力不断增长,收敛变形量大。对于土质隧洞,钢拱架在限制围岩变形方面比钢格栅更为显著,考虑造价等因素,应根据不同地质条件、埋深合理选择支护方式。
[Abstract]:Based on the site monitoring data of the Xinjiang reservoir diversion tunnel, the deformation characteristics and influencing factors of the saturated soil tunnel are deeply analyzed. According to the leading influence factors, the deformation of the soil tunnel is divided into 3 stages: the lateral spatial effect influence phase, the longitudinal space effect + time effect phase and the time effect phase, the lateral spatial effect. The main factors of collapse and roof fall should be influenced by the way of overbearing and reducing the lateral space area. The longitudinal space effect + time effect dominates the deformation of the second stage, and the reasonable separation can provide the basis for the parameter inversion; the time effect of the third stage is mainly rheological deformation. The analysis of the deformation data under the influence of the type of surrounding rock and the strength of the support shows that the low liquid limit powder (clay) has a better integrity, and the deformation is mainly related to the buried depth, the greater the depth, the greater the deformation and the certain rheological properties, and the great drainage of the silt and the fine sand pebbles, and it is easy to occur during the excavation. The deformation of the small range is mainly due to the loosening and deformation in the certain scope of the hole, and it has a great relationship with the position of the sand layer. The deformation of the buried depth has little influence on the deformation. The deformation of the supporting structure is very poor in the vault and the side wall. The deformation of the vault is short and the deformation is small. The plastic zone range of surrounding rock at the surrounding wall of the low liquid limit powder (clay) soil increases with the depth of the burial depth, the stress release time effect is obvious, the deformation pressure increases and the convergent deformation is large. For the soil tunnel, the steel arch frame is more significant than the steel grid in limiting the deformation of the surrounding rock, and the cost should be considered. According to different geological conditions, the support method should be chosen rationally.

【作者单位】：西安理工大学岩土工程研究所;
【基金】：国家自然科学基金资助项目(51179153)
【分类号】：U455.49

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