To control the height and recoil distance of a frame-shear wall structure after demolition by blasting,a frame-shear wall residential building demolition project in Qingdao was chosen as the subject.The simulation analysis used ANSYS/LS-DYNA software and the orthogonal combination of collapse angle and crotch extension time differ-ence.Firstly,a finite element model of the original scheme was built,and the model's validity was checked by compa-ring the variance between the model prediction and actual outcomes.Then,the trends of the structure recoil distance and burst pile height with the change were analyzed by changing simply the model's inter-span extension time differ-ence and cut height.Furthermore,the semi-quantitative formulas for the relationships between recoil distance and burst height with notch height and inter-span delay time difference were proposed based on the outcomes of multi-scenario numerical simulation,which were allowed for the determination of the inter-span delay time difference and notch height for the cases of minimum structural recoil distance and burst height,respectively.Finally,the analysis was carried out on the acceptable span-to-span extension time difference and the range of blasting notch heights for demolition blasting of frame-shear wall structures.The results show four fundamental steps to the collapse of frame-shear wall structures:blast notch creation,destabilized overturning,notch closure,and landing collapse.The study's findings indicate that the recoil distance of each model primarily increases at first and then decreases as the inter-span extension of the blast section is prolonged at the same cut height.Meanwhile,there is a more significant dispari-ty in the structure's recoil distance as the deferred time difference is extended,and the recoil distance increases with the height of the blast cut at the same inter-span extension.Additionally,the height of the detonation pile roughly de-creases as the time lag increases.The shear walls simultaneously improve the structural integrity and prevent the building from collapsing during the collapse,resulting in better structural integrity after collapse.The structure re-duces recoil distance when employing a short incision height and a 200 ms extension time difference.The most minor burst heights of the structures are those with considerable notch heights and a 300 ms delay time difference.A crotch delay time difference of between 270 and 420 milliseconds is adequate.More importantly,a large blast cut can lower the pile's height,while a tiny blast cut can effectively regulate the recoil.It can be reasonably chosen based on the demands of the area around the structure that will be torn down.The study can provide a guide for determining the in-cision height and delay time difference for demolishing frame-shear wall structures by blasting.
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