HDPE双壁波纹管-CIPP内衬复合结构受力特性研究

Bearing characteristics of HDPE double-wall corrugated pipe-CIPP lining composite structure

原位固化法(CIPP)可用于修复高密度聚乙烯(HDPE)双壁波纹排水管,但目前没有合适的模型来量化评估修复后整体结构的承载特性,修复设计无据可依。为此,首先基于叠合曲梁模型和复合曲梁模型对修复结构整体的受力特性进行理论分析,然后结合室内平板荷载试验对理论模型开展验证分析,最后通过室内土箱试验研究,探明了CIPP内衬对既有管道承载能力的提升作用,揭示了复合结构的破坏模式,以及既有管道的椭圆缺陷对CIPP修复效果的影响。研究结果表明:(1)自然固化CIPP内衬体系应采用叠合曲梁模型,紫外光固化CIPP内衬体系应采用复合曲梁模型;(2) CIPP内衬-柔性管道复合结构在外荷载作用下可能发生界面剥离,导致承载能力和刚度降低;(3) CIPP内衬可以提高复合结构的环刚度,增强其抵抗外荷载的能力,有效降低土体承受的荷载,减小土体变形程度。研究成果可为HDPE双壁波纹管的CIPP修复设计提供数据支撑。

The cured in place pipe(CIPP)method can be used to rehabilitate high-density polyethylene(HDPE)double-wall corrugated drainpipe,but there is no suitable model to quantitatively evaluate the bearing characteristics of the rehabilitated integral structure,so the rehabilitation design is not based on any evidence.As a result,the theoretical analysis on the overall bearing characteristics of the rehabilitated structure was carried out based on the stacked curved beam model and composite curved beam model.The theoretical model was verified and analyzed by indoor flat plate loading test.Through the indoor physical model soil box test,the effect of CIPP lining on the bearing capacity of the existing pipeline was proved,the failure mode of the composite structure was revealed,and the influence of the existing pipeline elliptical defect on CIPP rehabilitation effect was revealed.The main research results are as follows:①the natural curing CIPP lining system should adopt a stacked curved beam model,and UV curing CIPP lining system should adopt a composite curved beam model.②The interface debonding of CIPP lining-flexible pipe composite structure can occur under external load,resulting in the decrease of bearing capacity and stiffness.③CIPP lining can improve the ring stiffness of the composite structure,enhance its ability to resist external loads,effectively reduce the load borne by the soil,and reduce the degree of soil deformation.The research results can provide data support for CIPP rehabilitation design of HDPE double-wall corrugated pipe.