Arch dam safety evaluation method based on geomechanical model comprehensive method test

Abstract

The invention discloses an arch dam safety evaluation method based on a geomechanical model comprehensive method testThe method comprises the following steps: S1, building a comprehensive method testsafety evaluation index system according to detected data; s2, constructing an abrupt change model for evaluating the safety degree of the arch dam; s3, standardizing each underlying index of the comprehensive method test, and converting the underlying indexes into dimensionless data between 0 and 1; s4, performing mutation level calculation by using a normalization formula, and solving a total mutation level value of the target layer; s5, repeating the steps S1-S4, respectively calculating arch dam safety total abrupt change level values under different overload coefficients in the comprehensive method test, drawing a relation curve graph of the total abrupt change level values and the overload coefficients, and obtaining a high arch dam comprehensive method test safety coefficient according to inflection points of the relation curve of the total abrupt change level values and the overload coefficients; and S6, evaluating the overall stability and safety of the arch dam project by integrating the factors. According to the invention, the existing deformation monitoring data in the model comprehensive method test is utilized to establish a comprehensive evaluation system for the safety degree of the high arch dam comprehensive method test.

Description

technical field [0001] The invention relates to the field of dam safety evaluation methods, and more specifically relates to an arch dam safety evaluation method based on geomechanics model comprehensive method test. Background technique [0002] In the past 20 years, China has successively built 7 ultra-high arch dams with a dam height exceeding 200m, namely Ertan (240m, the maximum dam height, the same below), Laxiwa (250m), and Goupitan (230.5m). , Xiaowan (294.5m), Xiluodu (285.5m), Jinping Level 1 (305m) and Dagangshan (210m). Among them, Jinping I, Xiaowan and Xiluodu are 3 arch dams with a height of 300m, ranking among the top 3 highest arch dams in the world. The ultra-high arch dams under construction or to be constructed include Baihetan (289m), Wudongde (270m), Yebatan (217m), Dongzhuang (230m), Longpan (277m), Songta (313m), Ma Ji (300m), Tongka (278m), Nujiang Bridge (291m), Rolla (295m), etc. These ultra-high arch dam projects have made significant contribut...

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Problems solved by technology

[0008] (2) The other is the data processing of model monitoring. The current data processing is to draw the relationship curves of displacement, strain, strength reduction coefficient and overload coefficient in Excel software, and then analyze the test by artificially observing the laws of these curves. However, this analysis method has the influence of human subjective factors, which may lead to different results obtained by different people (as described in the comparative document 1 (thesis title: Displacement Information Monitoring and Research in Geomechanical Model Tests) Its application in engineering, the source of the paper: "Journal of Sichuan University (Engineering Science Edition)")), and due to the influence of factors such as the complex structure of the geomechanics model test, the accuracy of model processing, and the equivalent application of loads, the deformation Surveillance data have large uncertainties

However, the abnormal value of the monitoring data can accurately feed back the instability and failure information of the model test. Especially for high arch dam projects, there is no unified understanding of the discrimination basis for the failure stages of initial cracking, large deformation, and ultimate instability. Therefore, it is found that in the monitoring data Hidden outliers become difficult, and it is necessary to propose objective basis for judgment through mathematical methods

[0009](3) In addition, in terms of safety evaluation of high arch dam comprehensive method test, methods such as sudden change of deformation monitoring curve, model cracking and crack penetration are usually used in the model test. Inferring the safety of high arch dams, however, the sudden change criterion of the deformation monitoring curve is closely related to the selection of sensitive monitoring points, and the deformation monitoring results are greatly affected by factors such as model scale, simulation method, and equipment accuracy. In the safety evaluation, there is no comprehensive evaluation standard and system for the distribution range and value of the large deformation safety factor. Therefore, how to use the existing deformation monitoring data in the model comprehensive method test to establish a comprehensive evaluation of the safety degree of the high arch dam comprehensive method test system, not yet

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