A detection method for the impact of underground construction on ground building structures

Abstract

The invention belongs to the technical field of geology prediction, and relates to a method for detecting influence of underground construction on a structure of a ground building. The method comprises the following steps: firstly detecting a ground subsidence value and the vibration of a concrete construction during blast, determining surface movement parameters by using a random medium theory back analysis method, adopting a population-level-based adaptive genetic algorithm, and using a back analysis calculation program prepared by Matlab to perform back analysis of the surface movement parameters; calculating the ground subsidence value by a random medium theory according to the obtained surface movement parameters; and building a concrete construction finite element model after detecting the concrete construction and component sizes on site, then calculating concrete construction stress of the ground building under the action of subsidence and blast, and lastly extracting the stress and performing quantitative damage prediction on the ground building structure. The process principle of the design is scientific and reliable, the data acquisition is simple and accurate, the calculation analysis is good in reliability and high in precision, the prediction result is accurate, the safety is good, and environment protection is realized.

Description

Technical field: [0001] The invention belongs to the technical field of geological prediction, and relates to a quantitative detection method for damage to ground concrete structures affected by underground construction such as subway tunnel excavation, in particular to a detection method for the impact of underground construction on ground building structures. Through on-site detection, calculation analysis, Program implementation and numerical simulation are used to quantitatively predict the damage state of the concrete structure of the ground building affected by the drilling and blasting method of the subway tunnel. Background technique: [0002] At present, there is no open and effective detection method on the market in the aspect of quantitative prediction of concrete structure damage affected by drilling and blasting excavation of subway tunnels. In terms of the impact of surface subsidence caused by tunnel excavation on buildings, Yi Xiaoming and Zhang Dingli combi...

AI Technical Summary

Problems solved by technology

[0002] At present, there is no open and effective detection method in the market for the quantitative prediction of concrete structure damage affected by the drilling and blasting method of subway tunnels

In terms of the impact of surface subsidence caused by tunnel excavation on buildings, Yi Xiaoming and Zhang Dingli combined the engineering practice of the Xiamen Airport Road tunnel passing through the building complex, and respectively adopted the W-W failure criterion, the yield proximity model and the Mazars damage model to analyze the ground surface. The quantitative calculation and evaluation of the deformation and cracking of the house shows that the yield proximity model is essentially a generalized plastic zone, and the result is a quantitative distribution of the cracking safety degree of the house; the Mazars damage model is a typical tensile damage model. According to its damage variable At the same time, based on the yield proximity model and the Mazars damage model, the numerical simulation of the tunnel underpassing process is carried out. Non-linear correlation, thereby realizing the quantitative evaluation and control of the whole process of building deformation and cracking; the research results show that the calculation and evaluation results of the cracking process are in good agreement with the on-site cracking and deformation measurement results of the house, but this method is mainly for masonry structure, the failure criteria used are also suitable for masonry structures, which cannot accurately predict the damage and cracking of concrete structures; in addition, Yang Junsheng applied the stochastic medium theory to analyze the ground settlement, surface horizontal deformation and The inclination of the ground surface was analyzed in depth. On this basis, by summarizing the protection grades and allowable deformation values ​​of buildings at home and abroad, the impact of ground deformation caused by tunnel excavation on buildings was analyzed in detail, and finally the tunnel construction was summarized. The impact assessment method on buildings, but this method is only a general assessment of the buildings above the tunnel, not limited to the assessment of a specific single structure, and this single structure often needs to be analyzed separately according to the specific situation. At the same time, its damage The evaluation criteria are only applicable to ordinary masonry structures, and other studies are limited to qualitative evaluation of the impact of surface deformation caused by tunnel excavation on buildings; in terms of building damage caused by blasting vibration, Zhang Yuxu et al. For the safety assessment of building structures under the action of seismic waves, a comprehensive evaluation of the safety of blasting seismic waves by using elastic-plastic time-history analysis method is proposed. The elastic-plastic time-history analysis of the frame masonry structure on the ground floor of the first floor was carried out, and the stress, bending moment, and displacement of the frame structure were obtained, but it was impossible to quantitatively analyze the damage caused by the specific blasting seismic wave to the building; Tan Wenhui et al. A three-storey frame structure building near the shoulder of the boundary slope of the open-pit mine was taken as the research object. Through the field blasting vibration measurement, numerical simulation and theoretical analysis, the fatigue damage model of reinforced concrete components and the overall structure under the action of frequent blasting vibrations was established. The law of structural displacement, stress and stiffness changes under the action of frequent blasting vibrations has been studied. The research shows that under the action of frequent blasting vibrations, the damage caused by components is greater than the damage caused by the overall structure; the weakest part of the frame structure is the top floor of the structure As well as the top of the side column at the bottom of the structure, this research can provide a reference for the structural design of controlled blasting in open-pit mines and near-mine buildings. This method uses the modal change (first-order or finite-order natural vibration period change) after the blasting vibration of the frame structure To reflect the attenuation of structural stiffness, that is, the overall damage of the structure, and then evaluate the damage degree of the structure. This evaluation method is relatively vague, and the change of the mode cannot correspond to the damage of the structure quantitatively; other studies such as Wei Haixia et al. Monitor points in the building in the blasting area, conduct quantitative and qualitative analysis on the field measured data, and use the multi-resolution wavelet analysis method to obtain some characteristics of the velocity response of the building structure under the action of blasting seismic waves; Chen Shihai et al. use finite element time-history analysis Discusses the dynamic response of structures under different blasting vibration frequency and velocity loads, and points out that the seismic safety standards of structures are based on the peak value of vertical load velocity at high frequencies and the peak value of horizontal load velocity at low frequencies; the studies listed above The response characteristics of buildings are analyzed from the perspective of blasting vibration wave characteristics, and the damage and cracking of concrete structures cannot be quantitatively analyzed.

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