Study On Applicability Of Trenchless Rehabilitation Techniques In Municipal Sewer Works For Guangzhou

The municipal sewer rehabilitation in Guangzhou, faced with the lack of information, high costs, high waste and other problems. Reference to the advanced rehabilitation technologies and experience in the domestic and foreign constructions, the selection and design of rehabilitation techniques as well as construction management of security and reliable were studied in this paper.Analysis the informations of the inspection of Guangzhou sewers, the fundamental state of sewers’material, diameter, depth and defect was got, and the existing problems and repair target were cleared. Selected two typical representative pipeline segments marked A and B to study the selection and design of rehabilitation techniques as well as construction management of security and reliable. The material of the selected segments were both concrete, the diameter of A was400mm, B was800mm, the buried depth of A was3.2m and B was4.4m, and the repair index of A and B respectively was6.4and6.9.Analytic hierarchy process(AHP) was used in the sewer rehabilitation technology decisions. Compared of the common rehabilitation techniques in domestic, Spiral wound lining, cured-in-place pipe(CIPP) and slip lining was considered to be more applicable rehabilitation method in Guangzhou. Then, the construction condition, cost and benefit of segment A and B was futher analysed. The Priorities of rehabilitation technologies for A and B were woked out:Spiral wound lining was preferred for A and Cured-in-place pipe was for B.A was designed to be repaired by spiral wound lining, in the progress which the compressive strength and hardness was studied. The minimum design strength was0.022MPa and the minimum design hardness was15.8×103MPa·mm3.B was designed to be repaired by cured-in-place pipe, and the wall thickness of the liner and the influence of parameters changes was analysed. The design wall thickness was32mm and the ovality correction factor C was the maximum impact parameter. Hazard analysis and critical control point (HACCP) method was used to manage the rehabilitation construction process.32kinds of potential risk factors and20kinds of critical control points were studied by monitoring and management analysis of spiral wound lining.37kinds of potential risk factors and24critical control points in cured-in-place pipe.The results of this research will provide a theoretical basis and technical support for construction and management of trenchless rehabilitation technology in Guangzhou and other cities. Also, The methods of this research can be extended to the construction of underground pipeline infrastructure.