透水管桩抗弯性能试验研究

Experimental study on flexural properties of permeable pipe pile

透水管桩通过在桩身预留透水孔,联通土体,释放超静孔隙水压力,可加速沉桩过程桩周土的固结,有效减小沉桩挤土效应;但是,预留孔不可避免地会破坏桩身结构的完整性,为了探讨开孔对透水管桩抗弯抗裂性能的影响,开展了普通管桩与透水管桩的抗弯试验,记录了各桩的开裂弯矩、破坏弯矩以及不同弯矩作用下的桩身挠度与裂缝宽度,探讨了开孔对透水管桩抗弯抗裂性能的影响。研究表明,相对普通管桩,透水管桩跨中挠度更大,开裂弯矩降低,但仍满足规范要求;在相同弯矩作用下,透水管桩裂缝宽度小于普通管桩;在以相同裂缝宽度(1.5mm)作为极限状态判断标准的条件下,透水管桩的破坏弯矩大于普通管桩,透水管桩拥有优于普通管桩的抗弯性能。

Permeable pipe piles have water holes in the pile body to communicate with the soil and release the super-static pore water pressure, which can accelerate the consolidation of the soil around the pile and effectively reduce the squeezing effect of the pile. However, the reserved holes will damage the integrity of the pile shaft structure. In order to explore the effect of holes on the flexural and crack properties of permeable pipe piles, the flexural tests of ordinary pipe piles and permeable pipe piles were carried out, and the cracking flexural moments of each pile were recorded. The damage flexural moment and the deflection of the pile body and the crack width under the action of different flexural moments, the effects of openings on the flexural and crack properties of pervious pipe piles were discussed. The research shows that, compared with ordinary pipe piles, the permeable pipe piles have greater deflection in the mid-span and the cracking moment is reduced, but still meets the requirements of the code;under the same flexural moment, the crack width of the permeable pipe piles is smaller than that of ordinary pipe piles;under the condition that the same crack width(1.5 mm) is used as the criterion for determining the limit state, the flexural moment of the permeable pipe pile is greater than that of the ordinary pipe pile, and the permeable pipe pile has a better flexural property than the ordinary pipe pile.