诸暨市应店街镇崩滑流形成机理与致灾模式分析

Analysis of the Formation Mechanism and Disaster-Causing Patterns of Landslides, Debris Flows in Yingdianjie Town, Zhuji City

摘要: 本文以浙江省诸暨市应店街镇为研究区，针对该区域典型的地质灾害——崩塌、滑坡、泥石流(合称“崩滑流”)开展形成机理与致灾模式研究。研究区属低山丘陵地貌，地质构造复杂，岩性以凝灰岩、花岗岩等为主，风化强烈，为崩滑流的发生提供了物质基础与地形条件。研究结果表明，其形成机理是“内在条件”与“外在诱因”共同作用的结果。内在条件主要包括陡峻的斜坡地形、松软破碎的岩土体结构以及密集的节理裂隙；外在诱因则以强降雨为主导，尤其是梅汛期和台风雨的持续高强度降水，导致岩土体饱和、自重增加、力学强度骤降，从而诱发崩塌与滑坡。人类工程活动，如切坡建房、公路开挖等，则进一步破坏了斜坡的天然稳定性。基于此，总结出其致灾模式主要表现为三种：1) 区内地质灾害形成过程中，地形地貌、岩土体性质是孕灾地质条件，降雨及人类工程活动为关键致灾因子；2) 从地质灾害成灾模式分析，区内滑坡主要为土质或岩土质滑坡，主要成灾模式是降雨型滑坡，滑动形式以推移式为主；3) 崩塌主要为岩质崩塌和岩土质崩塌两类，岩质崩塌致灾模式主要为倾倒式、岩土质崩塌致灾模式为滑移式。

Abstract: This study focuses on Yingtianjie Town, Zhuji City, Zhejiang Province as the research area to investigate the formation mechanisms and disaster-causing patterns of typical geological hazards, specifically collapses, landslides, and debris flows. The research area is characterized by low-lying mountainous and hilly terrain with complex geological structures. The dominant rock types are tuff and granite, which are highly weathered, providing the necessary material foundation and topographic conditions conducive to the occurrence of collapses, landslides and debris flows. The research findings indicate that the formation mechanism arises from the combined influence of “internal conditions” and “external triggers”. The internal conditions primarily consist of steep slope terrain, a loose and fragmented rock and soil mass structure, and well-developed joints and fractures. The external triggers are predominantly heavy rainfall, particularly prolonged high-intensity precipitation during the plum rain season and typhoon-related rainfall, which leads to saturation of rock and soil masses, increased self-weight, and a sharp reduction in mechanical strength, thereby inducing collapses and landslides. Human engineering activities, such as residential construction and road excavation, further compromise the natural stability of slopes. Based on this analysis, the disaster-causing patterns are categorized into three main types: 1) In the process of geological hazards development in the region, topography and geomorphology, as well as the physical and mechanical properties of rock and soil masses, constitute the fundamental geological conditions for geological hazards, whereas rainfall and human engineering activities serve as the primary triggering factors; 2) Landslides in the area are predominantly of the soil or rock-soil type, with rainfall being the dominant trigger, and the failure mechanism primarily characterized by translational sliding; 3) Collapses are mainly classified into rock falls and rock-soil collapses, with the former typically occurring through toppling failure and the latter through sliding failure.