Four-layer pavement modulus back calculation method based on FWD deflection basin geometrical characteristics

A technology of geometric features and deflection basins, applied in the field of four-layer modulus back calculation, can solve problems such as large differences, large errors, and non-convergence of back calculation results, and achieve the effect of small calculation value error and numerical stability
CN110765691APending Publication Date: 2020-02-07RES INST OF HIGHWAY MINIST OF TRANSPORT
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Patent Information

Authority / Receiving Office
CN Β· China
Current Assignee / Owner
RES INST OF HIGHWAY MINIST OF TRANSPORT
Publication Date
2020-02-07

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Abstract

The invention discloses a four-layer pavement modulus back calculation method based on FWD deflection basin geometrical characteristics. The four-layer pavement modulus back calculation method comprises the following steps: 1, calculating a theoretical deflection basin and corresponding characteristic values of a pavement to be subjected to back calculation by adopting an elastic layered system mechanical model; 2, establishing a relation model of an equivalent far-end deflection point and a soil foundation modulus by adopting a nonlinear function; 3, establishing a relation model of the deflection ratio of the central point and the modulus ratios of the surface layer and the base layer by adopting a nonlinear function; 4, establishing a relation model between the deflection ratio of the fourth point and the central point and the modulus ratio of the surface layer and the subbase layer by adopting a nonlinear function; and 5, extracting a geometrical characteristic value of the actually measured deflection basin according to the constructed relation model, and respectively and reversely calculating modulus parameters of each structural layer corresponding to the actually measured FWD deflection basin according to two different convergence discrimination modes of central point deflection and deflection basin area. The four-layer modulus back calculation result is stable, the difference between the four-layer modulus back calculation result and a theoretical calculation value is small, and a reliable basis can be provided for evaluating the actual modulus state of each structural layer of an in-service pavement.
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Description

technical field

[0001] The invention relates to a four-layer modulus inversion method based on the geometric characteristics of a FWD deflection basin, belonging to the technical field of road engineering. Background technique

[0002] FWD (Falling Weight Deflectometer) is one of the most advanced pavement non-destructive testing equipment in the world at present. The pavement deflection basin detected by FWD is obtained by a modulus inversion method to obtain the different structural layers. The modulus parameter is an effective method to evaluate the service state of each structural layer of the pavement in service.

[0003] The existing modulus inversion methods mainly include iterative method and database search method, which have been widely used in pavement engineering, but both have certain limitations. For example, the difference between the measured deflection basin and the theoretical deflection basin is large, and the back calculation of the measured deflection b...

Claims

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