Method for measuring dynamic horizontal resistance coefficient of excavated soil layer in deep foundation pit

Abstract

The present invention relates to a method for measuring the dynamic horizontal resistance coefficient of an excavated soil layer in a deep foundation pit, and belongs to the design field of excavatedsoil layer support in the deep foundation pit. The method comprises the following steps of: Step 1: arrangement of monitoring points for the displacement of the deep foundation pit and determination of monitoring methods; Step 2: determination of initial m-value of a soil layer in the deep foundation pit; Step 3: determination of a deformation reduction coefficient of the m-value of the soil layerin the deep foundation pit and a reduction m-value; Step 4: determination of the equivalent internal friction angle of the soil layer in the deep foundation pit; Step 5: determination of a dynamic m-value BP neural network prediction model structure for the soil layer in the deep foundation pit; Step 6: learning and training, and verification of the BP neural network prediction model; and Step 7:prediction of the dynamic m-value of the excavated soil layer in the deep foundation pit. According to the method disclosed by the present invention, based on a neural network model, the process of dynamic change of the m-value of the soil layer with excavation of the foundation pit is effectively reflected, a prediction model for the dynamic m-value of the excavated soil layer in the deep foundation pit is established, and collapse of the foundation pit caused by excessive deformation of the foundation pit supporting structure can be effectively prevented.

Description

technical field [0001] The invention relates to a method for measuring the dynamic horizontal resistance coefficient of a deep foundation pit excavation soil layer, which belongs to the field of deep foundation pit excavation soil layer support design. Background technique [0002] As urban construction enters the fast lane of development, high-rise and super high-rise buildings have sprung up like mushrooms after rain. At the same time, due to the increasing shortage of urban land space, people began to develop and utilize underground space, resulting in deeper excavation of building foundation pits, followed by the problem of deep foundation pit support, resulting in foundation pits The problem of pit stability has become a "bottleneck" in the development of urban buildings. The design of deep foundation pit support structure has always been a very complicated geotechnical engineering problem, and foundation pit collapse accidents often occur due to unreasonable support s...

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Problems solved by technology

Therefore, the value of the m value of the soil layer is one of the important reasons related to the safety of the foundation pit support structure. If the value of this parameter cannot be reasonably selected, even if there is an accurate calculation model, no good evaluation results will be obtained.

At present, the m value of the soil layer is considered as a fixed value in the design of the supporting structure. Excavation is a dynamically changing quantity. Obviously, it is unrealistic to consider the m value of the soil layer as a fixed value

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