A method for determining the sequence of blasting demolition of support beams in deep foundation pits

Abstract

The invention relates to a method for determining a blasting demolition order of deep foundation pit support beams. According to the technical scheme, the method comprises the steps of partitioning the deep foundation pit support beams, building a deep foundation pit support beam finite element model, determining an area with the maximum average pressure value on the deep foundation pit support beams to be the finally demolished area N<M> and determining front-section ultimate compressive bearing capacity N<pressure> and front-section ultimate tensile bearing capacity N<tension> of the deep foundation pit support beams; eliminating the firstly demolished preliminary demolition scheme conforming to the condition according to the maximum displacement U of the deep foundation pit support beams, the maximal pressure f<pressure> of the deep foundation pit support beams and the maximum tension value f<tension> of the deep foundation pit support beams and employing the minimum value of the maximum displacement U of the deep foundation pit support beams as the firstly demolished preliminary demolition scheme; in a similar way, obtaining a second demolition scheme area, a third demolition scheme and a fourth demolition scheme; and finally determining the local demolition order of the areas. The method can meet the actual bearing requirements; the safety of constructors and surrounding buildings and structures can be ensured; the method conforms to the blasting construction characteristics; and the operability is high.

Description

technical field [0001] The invention belongs to the technical field of blasting demolition of support beams. In particular, it relates to a method for determining the blasting demolition sequence of support beams in deep foundation pits. Background technique [0002] With the development of urban construction, domestic high-rise buildings are increasing day by day, and correspondingly, large-scale deep foundation pit supporting beam demolition projects have also increased in large numbers, making the deep foundation pit supporting beam demolition technology widely concerned. The blasting demolition method is widely used in China because of its high efficiency, short construction period and moderate cost for demolishing support beams in deep foundation pits. For the blasting demolition of large deep foundation pit supports, the safety of blasting demolition mainly considers two aspects: one is the impact of blasting on the stability of deep foundation pits, and the other is ...

AI Technical Summary

Problems solved by technology

This demolition method often has a certain degree of blindness and cannot guarantee the safety and reliability of construction.

Demolition construction without scientific basis may lead to accidental damage to the support system of the deep foundation pit, mainly including: partial tensile damage or compression damage of the support beam, causing accidents; instability of the support beam as a whole, resulting in collapse accidents; The large displacement and deformation of the supporting piles around the foundation pit will cause the foundation pit to collapse and damage the surrounding structures; it will cause life hazards to the construction workers

[0004] Therefore, the existing deep foundation pit support beam demolition construction has great potential safety hazards and unscientific

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