Soil parameter dynamic inversion analysis method suitable for suspended deep foundation pit engineering

Abstract

The invention provides a soil parameter dynamic inversion analysis method suitable for a suspended deep foundation pit engineering, which can circularly optimize inversion parameters and use the optimized parameters in numerical value simulation prediction. According to on-site monitoring conditions and parameter sensitivity analysis, an inversion target and the reverse parameters are determined.Aiming at a multivariable problem of multiple soil layer parameters and multiple excavation step working conditions, a soil layer weight and an excavation step weight are introduced through calculation of an interval influence coefficient, the multivariable problem is converted into a single variable problem, and interval optimization analysis is executed through a least square method so as to determine an soil optimal parameter. In the soil parameter dynamic inversion analysis method, a foundation pit excavation order is taken as a back analysis progressive order, circulating calculation analysis of 'inversion-prediction-inversion again-prediction again' is executed for the parameters, with increase of excavation depth and the number of the soil layers, the soil parameters are continuously subjected to dynamic inversion and modification, the optimized parameters are used to the numerical value simulation prediction, and compared with actual monitoring values, feasibility of the inversion analysis method is verified, prewarning is provided for construction of the suspended deep foundation pit engineering, and thus, the soil parameter dynamic inversion analysis method has relativelyhigher application value.

Description

technical field [0001] The invention relates to a soil parameter inversion method, which relates to the fields of geotechnical engineering and tunnel engineering, and specifically relates to the field of deep foundation pit engineering. Background technique [0002] When supporting the foundation pit, a drop-bottomed enclosure structure is usually selected and extended into the water-resistant bottom plate to cut off the hydraulic connection between the inside and outside of the foundation pit. The suspended enclosure structure cannot penetrate the aquifer. During the excavation of the foundation pit, the precipitation in the pit will cause the water level outside the pit to drop, which in turn will lead to uneven settlement of the surrounding surface or swelling of the pit bottom, and cracks and settlement of surrounding buildings. In order to ensure the safety of the foundation pit and its surrounding environment, foundation pit monitoring methods are usually used to grasp...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a dynamic inversion analysis method of soil parameters suitable for suspended deep foundation pit engineering, which solves the problem that the existing foundation pit monitoring technology is difficult to predict the risk position in advance and there is a construction safety risk, And when the traditional numerical simulation method is applied, the results of a test usually used to determine that there is a large deviation between the soil layer parameters and the actual data. The introduction is based on the monitoring situation and parameter sensitivity analysis to determine the inversion target and inversion parameters. By calculating the interval Influence coefficient, introduce soil layer weight and excavation step weight, transform multivariable problem into single variable problem, and use least square method to carry out interval optimization analysis to determine the optimal parameters of soil, and excavation sequence of foundation pit as inverse Analyze the progressive sequence, carry out the cyclic calculation and analysis of "inversion-prediction-re-inversion-re-prediction" on the parameters, continuously invert and correct the soil parameters dynamically with the increase of the excavation depth and the number of soil layers, and apply the optimized parameters Based on the numerical simulation prediction, combined with the monitoring data in the actual project, the model is repeatedly optimized, and the parameters are dynamically adjusted. The invention has a wide range of applications and provides effective early warning for the construction of suspended deep foundation pits, so that the construction can avoid risks within a reasonable range

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