基于桩网结构的反滤混凝土护坡在临河软土路基中的应用
张昊
中国铁建大桥工程局集团有限公司，天津 300300
摘要：为解决高速公路施工时临河软土路基的沉降控制、边坡稳定与生态保护协同优化等问题，基于津石高速公路第六标段实际工程案例，构建桩网-反滤协同理论模型，采用预应力高强混凝土（prestressed high-strength concrete，PHC）管桩和加筋垫层形成的桩网结构，结合反滤混凝土护坡的新方案，并与传统方法进行对比分析。研究结果表明：新方案有效提高了地基承载力和路基稳定性，工后沉降不大于52 mm，比传统方法减小37%，差异沉降小于2.0 mm/m；反滤护坡使孔隙水压力减小55.6%，安全系数比传统护坡方案增大14.4%；CO2排放减少27.6%，悬浮物排放减少78.2%，pH值回归中性（7.6），全生命周期成本降低19.6%，工期缩短66.7%。该方案有效解决承载力-沉降、水流-土体相互作用及施工窗口期限制三大矛盾，为类似临河软土路基工程提供高效、稳定、环保的解决方案。
关键词：桩网结构；反滤混凝土护坡；管桩；临河软土路基
Application of pile-net structure-based filter concrete slope protection in soft soil subgrade by the river
ZHANG Hao
China Railway Construction Bridge Engineering Bureau Group Co., Ltd., Tianjin 300300, China
Abstract: To address the issues of settlement control, slope stability, and ecological protection during the construction of highways on soft soil foundations adjacent to rivers, based on the actual engineering case of the sixth section of the Tianjin-Shijiazhuang Expressway, a pile-net-filtering collaborative theoretical model is established. The model employs a pile-net structure formed by prestressed high-strength concrete (PHC) piles and reinforced cushion layers, combined with a new scheme for filtering concrete slopes, and is compared with traditional methods. The research results indicate that the new scheme effectively improves the bearing capacity of the foundation and the stability of the subgrade, with post-construction settlement not exceeding 52 mm (37% less than traditional methods) and differential settlement less than 2.0 mm/m; the filtering slope reduces pore water pressure by 55.6%, and the safety factor increases by 14.4% compared to traditional slope protection schemes; the life-cycle cost is reduced by 19.6%, construction time is shortened by 66.7%, carbon emissions are decreased by 27.6%, suspended particulate matter emissions are reduced by 78.2%, and the pH value returns to neutral (7.6). This scheme effectively resolves the three major conflicts of bearing capacity-settlement, water flow-soil interaction, and construction window limitations, providing an efficient, stable, and environmentally friendly solution for similar soft soil foundation projects adjacent to rivers.
Keywords: pile-net structure; filter concrete slope protection; pipe pile; soft soil subgrade by the river
