川藏铁路全线崩滑灾害类型、特征及其空间分布发育规律

频发的山地灾害是川藏铁路建设成功与否最为关键的因素之一。本研究结合野外调查遥感解译、数理统计等研究手段，对川藏铁路沿线崩滑灾害的类型、特征及其空间分布发育规律做了深入的分析和总结。研究查明川藏铁路沿线发育的崩滑灾害共747处，其中崩塌310处，滑坡413处，溜砂坡24处；全线崩滑灾害总体分布密度为0.40处/km，其中白玉至江达段最大，线密度为1.29处/km；对铁路工程存在潜在危害或影响的灾害点共258处，其中滑坡156处，崩塌91处、溜砂坡11处。此外，通过对崩滑灾害与主要孕灾背景因子的相关关系进行分析，发现崩滑灾害点的分布受岩性、构造、地貌及河流水系等因素的控制和影响，具有分布不匀、成群分布的特点。结合灾害发育程度指数与崩滑灾害发育程度分段标准，将铁路沿线崩塌滑坡的发育程度分为5个级别共14段，其中白玉至江达段、邦达至八宿段为极强发育段，天全至新都桥段、古乡至拉月段、朗县至加查段为强发育段。本研究可为川藏铁路的减灾选线及安全运营提供重要的科学决策支撑。

TYPES,CHARACTERISTICS AND SPATIAL DISTRIBUTION LAW OF LANDSLIDES AND COLLAPSES ALONG SICHUAN-TIBET RAILWAY

Frequent mountain hazards are one of the most critical factors for the successful construction of Sichuan-Tibet railway. Based on remote sensing interpretation, field investigation and mathematical statistics, we analyzed and summarized the types, characteristics and spatial distribution law of the landslides and collapses along Sichuan-Tibet railway. We identified 747 hazards along the railway, including 310 collapses, 413 landslides and 24 sand-sliding slopes. The average distribution line density of the hazards is 0.40 point/km, Baiyu to Jiangda section has the biggest line density(1.29 place/km). 258 mountain hazards have a potential threat and influence on the proposed railway engineering, including 156 landslides, 91 collapses and 11 sand-sliding slopes. In addition, we analyzed the relationship between the hazards and their impact factors. We found that the distribution of the hazards is comprehensively controlled and influenced by lithology, structure, geomorphology, river system and other factors, and has the characteristics of uneven and clustered distribution. On this basis, the development degree of landslides and collapses along Sichuan-Tibet railways was divided into 5 levels and 14 segments combining the development degree index of the hazards with the subsection standard. The Baiyu to Jiangda section, Bangda to Basu section are extremely strong development sections, Tianquan to Xindu section, Guxiang to Layue section and langxian to Jiachasection are strong development sections for the hazards. This study can provide an important scientific theory and decision-making support for line selection and safe operation of Sichuan-Tibet railway.