北京山区道路沿线崩塌灾害特征分析与防治思路探讨

Characteristics analysis and prevention discussion of collapse disasters along roads in mountainous areas of Beijing

崩塌是北京地区数量最多、分布最广的突发地质灾害类型。根据2011—2021年应急调查统计,道路沿线崩塌灾害占已发生灾害的65.7%,严重影响行人、游客及车辆安全。崩塌规模一般介于几十至几百立方米,极个别超过5000 m^(3);崩塌灾害具有很强的继发性,同一路段斜坡发生崩塌后还会连续发生;汛期强降雨仍是崩塌灾害发生的主要诱发因素,6—8月,崩塌灾害发生率占82%;砂岩孔隙率高,吸水性好,汛期砂岩斜坡发生崩塌概率高,非汛期白云岩岩质斜坡受冻涨作用影响容易发生崩塌。针对崩塌灾害存在的问题,如识别发现难、风险防控难、成灾模式复杂、治理效果不能满足防灾要求以及民众防范意识较弱等,提出了开展高精度调查和风险普查早期识别相结合、“人防+技防”、不同风险斜坡分级管控以及治理效果监测评价、多渠道科普宣传等措施,为北京市山区道路沿线崩塌风险防控、应急预案制定、防范措施实施提供了思路。

Collapse is the most numerous and widely distributed type of abrupt geological hazard in Beijing.According to the emergency investigations and statistics over the years,the collapse disasters along the road account for 65.7%of the hazards occurred,which seriously affects the safety of pedestrians,tourists and vehicles.Based on the statistical analysis of the collapse disaster data along the road in recent 10 years,it is found that the collapse scale affects tens to hundreds of square meters with some rare exceptions exceeding 5000 m^(3).The collapse hazards is highly secondary in nature,and often occur continuously after the first collapse in the same section;Heavy rainfall in flood season is still the main inducing factor.From June to August,the occurrence rate accounts for 82%.Sandstone has high porosity and good water absorption,and so the probability of collapse of sandstone slope in flood season is high.Dolomite rock slope in non flood season is prone to collapse under the influence of frost swelling.In view of the existing problems,such as difficult identification and discovery,difficult risk prevention and control,complex disaster mode,ineffective governance to meet the requirements of disaster prevention,and people’s weak awareness of prevention,this paper puts forward the combination of high-precision investigation and early identification through risk census,"people participation+technical prevention",hierarchical control of different risk slopes,monitoring and evaluation of governance effect,and multi-channel science popularization,which provide ideas for the prevention and control of collapse risks,the formulation of emergency plans and the adoption of effective preventive measures along mountain roads in Beijing.