北京市昌平区生态清洁小流域护坡技术工程示范与综合效益分析

为解决水土流失及水资源污染等问题，北京市提出三道防线的思想用于指导生态清洁小流域的建设.目前，以浆砌石为代表的河（沟）道护坡技术难以满足生态清洁小流域的需求，近自然的生态护坡措施已逐渐成为维护河（沟）道水土保持功能、减少水资源污染的重要生态措施.本文基于北京市昌平区生态清洁小流域示范区建设中采用的4种生态护坡工程，利用ANSYS有限元分析软件进行力学性能分析，并基于层次分析法对不同护坡工程的稳定性、经济性、生态性、适用性等指标进行综合效益分析.研究结果表明，混凝土护底的生态多孔砖护坡综合得分为0.3766，为4种生态护坡技术中的最优方案.在坡度适用范围内，相较于其他3种生态护坡技术，混凝土护底的生态多孔砖护坡技术能够大幅提升边坡稳定性（安全系数提高66.3%以上），同时保持较好的经济性（约400~550元·m^-2）.

Demonstration and comprehensive benefit analysis of slope protection project in ecological and clean small-watersheds in Changping District of Beijing

Beijing proposed three ecological fronts to build up ecological and clean small-watersheds in order to prevent soil erosion and water pollution. The conventional slope protection technology for rivers or ditches mainly using stone pitching has difficulty in satisfying the requirements of ecological and clean small-watersheds, so the near-natural ecological slope protection technologies have been more and more important in maintaining the water and soil conservation function and reducing water pollution of rivers or ditches. In this work, four kinds of ecological slope protection techniques were applied to the ecological and clean small-watersheds demonstration zones in Changping District of Beijing. The finite element analysis software ANSYS was used to analyze the mechanical properties. In addition, the analytic hierarchy was used to evaluate the economic, ecological, safety and applicability of different slope protection techniques. The results showed that the ecological porous brick slope protection with concrete base was the optimal solution among the four ecological slope protection techniques with a comprehensive value of 0.3766. Within the applicable range of slope gradient, the ecological porous brick slope protection with concrete base could significantly improve the stability of the slope compared with other techniques, with the safety factor increased by more than 66.3%, while maintaining competitive price of about RMB 400~550 per square meter.