Study On Key Techniques Of Blasting Demolition Of Deep Foundation Pit Support Beam

With development of urbanization,various large-scale deep foundation pits have also increased,and the amount of demolition of reinforced concrete suppo rt beams in foundation pits has also increased.The demolition of deep foundat ion pit support system by blasting method has the advantages of high efficienc y,short construction period,moderate cost,and which is widely used in practi ce.Most of the blasting demolition works in the foundation pit support are loc ated in the prosperous downtown area,which leads to a complex construction environment,high construction safety requirements,shorter and shorter requirem ents of the construction period.The safety is a special concern during construc tion.In particular,the demolition of large-scale deep foundation pits is mainly reflected in two aspects: first,the stability of the foundation pit during the bl asting construction,the second is the effect of semi-finished products,surroundi ng buildings and people in the foundation pit.Based on the theoretical analysis,numerical simulation and engineering ap plication,this paper reveals dynamic response of reinforced concrete under inte rnal blast load and the restraint effect of stirrups on reinforced concrete suppor t beams.And A method based on multi-curvature and coupleing hole-arrangem ent of blasting demolition of the deep foundation pit supporting beam and a li near cutting pretreatment technique for a deep foundation pit supporting beam are proposed.Practice shows that we will strengthen the control of various haz ards caused by demolition blasting,reduce the intensity and scope of blasting disasters,guarante the safety of blasting demolition of support beams for found ation pits,and further increase the efficiency and economic benefits of blasting demolition.It provides theoretical and technical support for blasting demolition technology of large deep pit support beams.