Reason Research Of Pipeline Rupture In Soil Nail Wall Of A Deep Excavation

Pit deformation size and supporting structure has a close relationship,over thenormal may caused by damage to the surrounding facilities and threaten thepitsecurity. In this paper,,relate to a deep foundation pipe rupture accident ofZhongshan,First according to thepit surrounding environment, the security level of theexcavation analysis and evaluation; Secondly, according to thepit deformationmeasured results, comparative analysis of deformation about supporting structure fordifferent sections of different pit, while the excavation of soil nailing walldeformation carried out theoretical calculations, based on this mechanism of soilnailing wall mechanical pipe rupture preliminary analysis through a comprehensiveanalysis of soil nailing wall to evaluate the reasonableness of the structure; Finally, ina natural pit, heap load, under heavy rain pipeline rupture area of excavation tosimulate the deformation characteristics. Gained some knowledge and conclusions areas follows.(1) The excavation pipeline rupture reason lies in ignoring the seriousconsequences arising sewage pipe rupture is disabled, so that the pit level of safetyhas design deviations. Therefore, Pit safety level design must pay more attention tothe surrounding environment and analyze and protect the severity of the consequencesof the destruction, there are differences between different sections of the samesurroundings excavation, concrete analysis to the specific environment, can notgenerally design.(2) Soil nailing support structure needs to rely on a certain displacement of thesoil in order to play its role in strengthening, soil nail wall showing large deformationcharacteristics during excavation, the use of soil nailing wall pit supporting structurein this article of pipeline rupture area, the wall close to the maximum horizontaldisplacement of6cm, surface subsidence close to5cm, there are differences with thesurrounding wall deformation, is one of the causes of brittle deformation pipeline rupture. Therefore, the existence of deformation around the pit to protect sensitiveobjects must be carefully selected soil nailing support structure.Select the supporting structure is a very rigorous work, different degrees ofdeformation Pit select different support structure generated by the selected supportstructure to ensure the security and stability of pit itself, while the surroundingenvironment must meet the Pit modification request. For the scope of excavation ofunderground pipes in the area of memory, be sure to pay attention to retainingstructure supporting selected.(3) The wall loads and heavy rains exacerbated pit deformation induced factorsprompting the pipeline rupture. In the pit project, should be prohibited in the top ofthe wall accumulate a lot of steel; due to the heavy rainfall infiltration can soften therock and soil, reduce excavation stability, so to backfill the excavation beforeconstruction, pay close attention to pit the top of the fracture cases If found cracksshould be repaired promptly.(4) Up to the area of numerical simulation of excavation pipeline rupture results:when the supporting structure of pit using a combination of soil nail wall steel pipepile and anchor miniature (anchor), along with the excavation, the horizontaldisplacement of the top wall have large deformation, lengthening the first soil nailwall top can better control the horizontal displacement; field meter pit pit pit wallcloser to the settlement, the greater the surface subsidence.In this article,the Research up to the actual cause of the accident by analyzingthe works acquired under similar engineering environment for selected security leveldesign and support structure has a certain reference and reference; Also has somepractical significance for studies of soil nail wall and composite soil nailing walls.