地铁工程附属结构暗挖施工地表铺设钢板的选型研究

针对地铁工程附属结构浅埋暗挖施工地表铺设钢板具体参数缺少量化研究的现状,通过现状资料的分析,并以解析计算与数值模拟计算为手段,系统分析钢板厚度、钢板铺设位置、钢板超出开挖轮廓线外宽度、覆土厚度等不同条件下路面车辆静荷载对暗挖附属结构的影响,研究结论:钢板厚度的变化对地层竖向位移场和应力场的分布影响较大,结构拱顶上方地面沉降与钢板厚度基本成反比关系,钢板厚度一般可取为2 cm;随着附属结构覆土厚度的增加,铺设钢板效果逐渐降低,一般在覆土厚度达到6 m时,路面铺设钢板已无必要。

Study on Type Selection of Steel Plate Laid on Ground Surface during Mining-method Construction of Accessory Structures of Metro Project

There was little quantitative research on specific parameters of steel plate laid on ground surface during shallowly-buried mining-method construction of accessory structures of metro project. To solve this problem,based on the analysis on the existing construction data,and by means of analytic solution and numerical simulation,the influence of vehicle static load on the mining-method accessory structure was systematically analyzed in this study under different conditions,including the different steel plate thicknesses,different positions of steel plate,different steel plate widths beyond the excavation contour line,different thicknesses of overburden layer and so on. Then this study come to the conclusion as follows:( a) The thickness of steel plate can greatly change the distributions of vertical displacement field and stress field of stratum; the ground settlement above the arch crown of the structure is inversely proportional to the thickness of steel plate; and it is advisable to use the steel plate thickness of 2cm in general.( b) With the increasing of the thickness of overburden layer above the accessory structure,theeffect of steel plate gradually decreases and its effect can be ignored when the thickness of overburden layer is deeper than 6m.