西部山区临近营业线铁路桥梁桩基施工方案比选研究

Study on Comparing and Selecting Scheme for Constructing Bridge Pile Foundation Adjacent to Business Line of Railway in Western Mountainous Area

针对西部山区地质地形复杂、施工难度大、安全风险高等特点,为选择适应山区临近营业线铁路桥梁桩基施工方案,建立模糊综合评价模型对桥梁桩基施工方案进行比选和排序.该方法根据决策专家的意见,建立模糊综合评价矩阵,并通过离差最大化法确定各评价指标的权重系数,实现专家经验的主观性和离差最大化法的客观性相结合.以渝黔铁路引入重庆枢纽工程为例,运用该模型对高强预应力管桩、泥浆护壁钻孔灌注桩、水磨钻挖孔灌注桩、内务沉管灌注桩4种桥梁桩基施工方案进行比选,计算结果表明:水磨钻挖孔灌注桩方案最优.工程实践表明,水磨钻挖孔灌注桩在山区临近营业线桥梁桩基施工中取得了较好的社会效益和经济效益,进而验证了该评价模型可行性和准确性.

It is characterized by complex geological terrain, difficult construction and high safety risks in the western mountainous areas. In order to select the suitable bridge pile foundation construction scheme for the adjacent railway in the mountainous area, a fuzzy comprehensive evaluation model was established to compare and select the bridge pile foundation construction scheme. According to the opinions of decision-making experts, the fuzzy comprehensive evaluation matrix was established, and the weight coefficient of each evaluation index was determined by the maximum dispersion method to realize the combination of subjectivity of expert experience and objectivity of maximum deviation method. Taking the project of introducing Chongqing-Guiyang Railway into Chongqing hub as an example, the model was used to compare and select four kinds of construction schemes, such as high-strength prestressed pipe pile, mud protection bored pile, water drilling bored pile and inner immersed tube cast-in-place pile. The calculation results showed that the water drilling bored pile scheme was optimal. The engineering practice showed that the water drilling bored pile had achieved good social and economic benefits in the construction of bridge piles adjacent to operating railway in the mountainous area, and verified the feasibility and accuracy of the evaluation model.