摘要
目前国内外鲜见高寒强震区岩屑堆积体的系统研究,拟建川藏铁路横穿青藏高原,区域内广泛分布有岩屑堆积体地貌,一些难以完全绕避的山麓坡地岩屑堆积体区域不得不以路基段通过,存在较高安全风险。本文基于沿线调研情况,对岩屑堆积体的分类、成灾机理做了深入总结,并提出针对性工程整治措施。从工程整治角度可将岩屑堆积体分成3类:①细颗粒岩屑堆积体,破坏特点是:浅表层、小规模、长期性,治理措施有树根桩坡面主动加固、增大挡墙高度、渡槽棚洞排导;②中等颗粒岩屑堆积体,危害方式主要是边坡开挖破坏或路基欠稳定,建议采用微型钢管桩超前支护开挖和回填路基;③大颗粒岩屑堆积体,危害方式主要是大块石冲击破坏,建议采用高能量级别的拦石挡墙并对关键构筑物如桥墩、路面等进行防护。
There is no existing systematic method that researching on talus deposit in extremely cold and earthquake area at home and abroad,proposed Sichuan-Tibet railway across the Tibetan plateau,talus deposit landform area widely distributed,which is difficult to pass round completely.The subgrade have to be constructed there,and therefore the railway operation faces high disaster risk.Based on the survey,the classification,mechanism of plague of the talus deposit has been in-depth summarized.By the analysis,the talus deposit is divided into three categories:①fine particulate talus deposit,with damage features of shallow,small-scale and long-term.The prevention and control measures include adopting the root pile,increasing the wall height,setting up the aqueduct and shed hole;②the medium particles talus deposit,with the hazard form of destabilization of the slope and subgrade.The recommended measure is to use the mini steel-tube pile subgrade in advance for excavation and to backfill on the subgrade;③ a large particles talus deposit,with the main harm of large stone impact.The suggested proposal is to use the high-energy rock retaining wall,and to protect the important structures such as bridge,subgrade surface.
引文
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