滇西南红层滑坡稳定性分析与评价

Analysis and evaluation of the stability of red-bedded landslides in southwest Yunnan

红层主要是指中生代以来的碎屑岩地层,在我国广泛分布。由于红层工程性质较差,在红层地区边坡工程常在降雨等作用下出现失稳。本文以云南景文高速公路滑坡为例,开展滑坡稳定性评价研究分析,研究结果表明:(1)滑坡的形成和发展变化受多种因素控制,其中地层岩性和地下水为主要成因。(2)红层泥岩具有强度低、遇水软化膨胀、失水干裂、崩解性强等特性。强降水和强蒸发使边坡地下水面附近岩体容易处于饱水-干裂-饱水的干湿循环状态,使岩体力学性质逐渐恶化。(3)红层滑坡滑动面多呈折线形,在计算滑坡稳定性时应结合现场实际情况,反演不同部位岩土力学参数,为滑坡防治提供计算依据。

The Red Formation is mainly a clastic formation from the Mesozoic onwards and is widely distributed in the country.Due to the poor nature of red layer engineering,slope works in red layer areas are often destabilised by rainfall and other effects.This paper takes the Yunnan Jingwen Expressway landslide as an example to carry out landslide stability evaluation research and analysis,The research results show that:(1)the formation and development of landslides are controlled by a variety of factors,of which stratigraphic lithology and groundwater are the main causes.(2)Red mudstone has low strength,softening and swelling with water,dry cracking with water loss and disintegration.Strong precipitation and evaporation make the rock near the groundwater surface of the slope susceptible to a dry and wet cycle of satiation-dry fracture-satiation,resulting in a gradual deterioration of the mechanical properties of the rock.(3)The sliding surface of red-layered landslides is mostly folded and linear.When calculating the stability of landslides,the geotechnical parameters of different parts should be inferred,taking into account the actual situation on site,so as to provide a basis for calculating landslide control.