装配式波纹钢综合管廊施工回填过程受力特性试验研究

Experimental study on mechanical characteristics of prefabricated corrugated steel utility tunnels during backfilling

装配式波纹钢综合管廊(Prefabricated Corrugated Steel Utility Tunnel,PCSUT)是一种新型管廊结构,为明确其施工回填过程结构受力特性,以河北省衡水市武邑县某多舱装配式波纹钢综合管廊工程为依托,选取了3个监测断面对回填过程中管廊综合舱及燃气舱的位移、应变、舱外土压力进行现场监测试验.结果表明:回填到综合舱拱顶时综合舱竖向位移及水平向位移相对较大,此时结构处于相对不利状态,回填到拱顶之后综合舱位移开始恢复;燃气舱由于其截面形状的特殊性,整体竖向位移值接近,水平向最大位移发生在拱腰位置;舱体应力可分解为弯矩引起的弯曲应力和轴力引起的轴向应力,设计计算过程须考虑弯矩和轴力的组合效应;管廊回填过程土-结相互作用明显,回填结束时舱外土压力沿拱轴线并非完全一致,其大小分布与主体结构相对于回填土体的位移状态有关.研究成果可全方面解释装配式波纹钢综合管廊施工回填过程受力特性,为后续研究、设计、施工提供案例支撑.

The Prefabricated Corrugated Steel Utility Tunnel(PCSUT)is a new type of utility tunnel structure.In order to clarify the mechanical characteristics of the structure,a field test is conducted.Three sections are selected for the field test of the comprehensive compartment and gas compartment during backfilling,based on a multi-compartment PCSUT in Wuyi County,Hengshui City,Hebei Province.Multiple responses are measured,including the displacement,strain,as well as earth pres⁃sure outside the structure.The results show that the vertical and horizontal displacement of the com⁃prehensive compartment are relatively large when backfilling to the crown position of the comprehensive compartment.After that,the displacement begins to recover.During backfilling,the vertical dis⁃placement of the gas compartment is similar along the arch axis,due to the particularity of its crosssection shape and the maximum horizontal displacement occurs at the arch waist position.The stress of the PCSUT is composed of bending stress caused by bending moment and axial stress caused by axial force.Therefore,when desiging the PCSUT,the combined effect of bending moment and axial force must be considered.During the backfilling process of the PCSUT,there is an obvious soil-structure in⁃teractive effect.At the end of the backfilling,the earth pressure outside the structure is not completely consistent along the arch axis.The magnitude of the pressure is related to the displacement of the struc⁃ture relative to the backfilled soil.The research results of this paper can fully explain the mechanical characteristics of the PCSUT during backfilling,providing case support for subsequent research,de⁃sign and construction.