Method for quickly predicting critical failure stress of subgrade soil

Abstract

The invention discloses a method for quickly predicting critical failure stress of subgrade soil. The method comprises the following steps: firstly, carrying out a static triaxial test on a subgrade soil test piece to obtain breaking stress under corresponding working conditions, and determining bias stress during repeated loading in a dynamic triaxial test by selecting a stress level on the basisof a static triaxial test result, thereby obtaining critical breaking stress of the subgrade soil test piece under the corresponding working conditions. Besides, a subgrade soil critical failure stress estimation model comprehensively considering confining pressure, water content, relative dry density ratio and plasticity index weight is established, and estimated model parameters are obtained through fitting according to dynamic triaxial test data, so critical failure stress values of different subgrade soil under corresponding working conditions are estimated through the established estimation model. According to the method, the influence of confining pressure, water content, relative dry density ratio, plasticity index weight and roadbed soil basic physical property parameters on subgrade soil critical failure stress is considered at the same time, so estimation precision and estimation efficiency are improved, and the problems that an existing estimation method is not comprehensive enough in consideration and a prediction process is complex are solved.

Description

technical field [0001] The invention belongs to the technical field of road engineering, and relates to a method for quickly predicting critical failure stress of subgrade soil. Background technique [0002] With the rapid development of our country's economy, roads are playing an increasingly important role. As of 2020, 150,000 kilometers of expressways have been opened to traffic in my country, and according to the planning objectives of the "National Highway Network Planning (2013-2030)", there will be 40,000 kilometers of expressways and 100,000 kilometers of ordinary national roads by the end of 2030 Urgently in need of construction. With the rapid development of the transportation industry, the problem of heavy and overloaded vehicles has become more and more prominent, which will lead to excessive permanent deformation of the roadbed under the condition of excessive load, which will cause various diseases on the road surface, such as rutting and cracking Wait. At th...

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Problems solved by technology

[0016] In order to solve the above problems, the present invention provides a method for quickly predicting the critical failure stress of subgrade soil, which simultaneously considers the influence of confining pressure, moisture content, relative dry density ratio, plasticity index weight, and basic physical parameters of subgrade soil on the critical failure stress of subgrade soil , which improves the prediction accuracy and efficiency, and solves the problem that the existing prediction methods do not consider the factors affecting the critical failure stress of subgrade soil comprehensively and the prediction process is complex and time-consuming.

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