CN-117966560-B - Method for evaluating grouting reinforcement effect of cement concrete pavement

CN117966560BCN 117966560 BCN117966560 BCN 117966560BCN-117966560-B

Abstract

The evaluation method of the grouting reinforcement effect of the cement concrete pavement comprises the steps of setting a plurality of test points in an evaluation road section before grouting, collecting deflection basin data of each test point by adopting a drop hammer type deflection meter, calculating comprehensive equivalent rebound modulus E Fi of the test points before grouting, and correcting the comprehensive equivalent rebound modulus E Fi to obtain a correction value E F by S1.2. After grouting, S2.1, collecting deflection basin data of each test point by adopting a drop hammer type deflection meter, S2.2, calculating the comprehensive equivalent rebound modulus E Bi of the test point after grouting, and S2.3, correcting the comprehensive equivalent rebound modulus E Bi to obtain a correction value E B . And S3, outputting an evaluation result of the grouting reinforcement effect according to the correction values E F and E B . The evaluation method can effectively improve the accuracy of the evaluation result.

Inventors

ZHOU WENPING
LIU XIAOQUAN
GU RONGJUN
HUANG HAIKUN
ZHANG JINGYAN
CAI BAIRONG
SHEN XIAOFENG

Assignees

常州市建筑科学研究院集团股份有限公司
江苏鼎达建筑新技术有限公司

Dates

Publication Date: 20260508
Application Date: 20240124

Claims (6)

1. The method for evaluating the grouting reinforcement effect of the cement concrete pavement is characterized by comprising the following steps of: Before grouting: S1.1, setting a plurality of test points in an evaluation road section; s1.2, collecting deflection basin data of each test point by adopting a drop hammer type deflection instrument; S1.3, calculating the comprehensive equivalent rebound modulus of the test point before grouting ; Comprehensive equivalent modulus of resilience of test point before grouting The calculation formula of (2) is as follows: Wherein, the The modulus of resilience of the whole of the base layer and the roadbed before grouting is expressed, Represents the modulus of resilience of the entire cement concrete pavement before grouting, Representing the structural layer allocation coefficients, , Represents the load diffusion coefficient of the pavement structure before grouting, Represents the deflection value of the load center of the drop hammer type deflection instrument before grouting, Representing the test load of the drop hammer type bending instrument, Representing the radius of a falling weight type bending instrument bearing plate; S1.4, the comprehensive equivalent modulus of resilience Performing correction to obtain a correction value ; The correction value The calculation formula of (2) is as follows: Wherein, the Represents the average value of the comprehensive equivalent rebound modulus of all test points in the evaluation section before grouting, The coefficient of the guaranteed rate is represented, The standard deviation of the combined equivalent rebound modulus of all test points in the evaluation section before grouting is shown, A correction factor indicating the structural layer compactness and modulus change due to traffic factors, The value range of (2) is 1-1.05; after grouting: S2.1, collecting deflection basin data of each test point by adopting a drop hammer type deflection instrument; S2.2, calculating the comprehensive equivalent rebound modulus of the test point after grouting ; Comprehensive equivalent rebound modulus of test point after grouting The calculation formula of (2) is as follows: Wherein, the Represents the overall modulus of resilience of the base layer and the roadbed after grouting, Represents the modulus of resilience of the whole cement concrete pavement after grouting, Represents the load diffusion coefficient of the road surface structure after grouting, Representing the deflection value of the load center of the drop hammer type deflection instrument after grouting; S2.3, the comprehensive equivalent modulus of resilience Performing correction to obtain a correction value ; The correction value The calculation formula of (2) is as follows: Wherein, the Represents the average value of the comprehensive equivalent rebound modulus of all test points in the evaluation section after grouting, Represents the standard deviation of the integrated equivalent rebound modulus of all test points in the evaluation section after grouting, Showing the supporting effect of hardening slurry in the grouting holes after grouting and the correction coefficient of the compactness and modulus change of the structural layer caused by grouting or traffic factors, The value range of (2) is 1.05-1.15; Evaluation: s3, according to the correction value And And outputting an evaluation result of the grouting reinforcement effect.
2. The method for evaluating a grouting reinforcement effect of a cement concrete pavement according to claim 1, wherein a load diffusion coefficient of a pavement structure before grouting is The calculation formula of (2) is as follows: Wherein, the 、、 Respectively represent deflection values of 300mm, 600mm and 900mm from the load center before grouting.
3. The method for evaluating a grouting reinforcement effect of a cement concrete pavement according to claim 1, wherein the load diffusion coefficient of the pavement structure after grouting is The calculation formula of (2) is as follows: Wherein, the 、、 Respectively represent deflection values of 300mm, 600mm and 900mm from the load center after grouting.
4. The method for evaluating the grouting reinforcement effect of a cement concrete pavement according to claim 1, wherein the evaluation result comprises the evaluation index of the evaluation result including the rate of increase of the integrated equivalent modulus of elasticity And the integrated equivalent rebound modulus values for different traffic classes.
5. The method for evaluating a grouting reinforcement effect of a cement concrete pavement according to claim 4, wherein the improvement rate of the composite equivalent modulus of elasticity is The calculation formula of (2) is as follows: when (when) And when the grouting reinforcement effect is not less than 10%, the grouting reinforcement effect is qualified.
6. The method for evaluating the grouting reinforcement effect of a cement concrete pavement according to claim 4, wherein the comprehensive equivalent rebound modulus values of different traffic classes include: when the traffic grade is extra heavy, the comprehensive equivalent rebound modulus value is not less than 120MPa; when the traffic grade is heavy, the comprehensive equivalent rebound modulus value is not less than 100MPa; When the traffic class is medium and light, the combined equivalent rebound modulus value should be no less than 80MPa.

Description

Method for evaluating grouting reinforcement effect of cement concrete pavement Technical Field The invention relates to the technical field of grouting reinforcement of pavement, in particular to an evaluation method of grouting reinforcement effect of a cement concrete pavement. Background Grouting reinforcement technology is widely applied to the aspects of road engineering foundation reinforcement, compaction, seepage prevention and the like. After the road grouting reinforcement, the grouting reinforcement effect needs to be detected and evaluated, and whether the grouting reinforcement effect meets the expectations is judged. At present, common grouting reinforcement effect detection methods comprise drilling coring, geological radar detection, drilling peeping detection and the like, and the methods are all qualitative evaluation, so that the problems of inaccurate and objective detection results exist. Regarding a series of methods for evaluating grouting effect by using the nondestructive testing at present, more or less defects exist, and objective evaluation of grouting effect cannot be accurately and effectively performed. In addition, various road grouting forms such as cement grouting, modified geopolymer grouting, high polymer grouting and the like exist in the market at present, a plurality of unit technologies are different, a fish is mixed, and a part of units have the idea that the slurry fluidity is not important, so long as grouting is performed, the larger the grouting pressure is, the better the grouting amount is, in fact, the more viscous the slurry is, the larger the grouting pressure is, the more the slurry amount is, the possibility of damaging the whole structure of a road is increased, so that each structural layer of the road is more loose, and the bearing capacity is reduced compared with that before grouting. For pavement structures, the base layer is always the main bearing layer of the pavement structure, and various researches show that for the existing roads taking cement stabilized macadam as the base layer, the weakening rate of the strength of the base layer is obviously larger than that of the upper base layer, and the reduction of the bearing capacity of the road is usually started from the fatigue failure of the base layer. The grouting utilizes slurry permeation, compaction and splitting effects, can effectively fill and improve the compactness of the roadbed and the subbase, and the grouting effect not only improves the elastic modulus of the roadbed, but also has obvious reinforcement effect on the junction of the base layer, the base layer and the roadbed. In the existing evaluation method, the rebound modulus of a roadbed or the rebound modulus of the whole pavement is directly adopted as an evaluation parameter to evaluate the grouting reinforcement effect, but in practical application, the following defects exist in the mode: 1. The grouting slurry has a certain reinforcing effect on the base layer, particularly the joint of the base layer and the roadbed, comprises the reinforcing of cracks of the base layer and the base layer, the area is a weak area of the road, and is just a grouting key area, the grouting reinforcing effect is particularly obvious, in addition, the slurry in the grouting holes is anchored with the base layer and the roadbed, a pile foundation similar to that in a house building is formed, the whole bearing capacity of the base layer can be greatly improved, and obviously, the grouting effect is inaccurately judged by only calculating the change of dynamic modulus before and after grouting of the roadbed. 2. The road reinforced by grouting has damage to most of road surfaces, and the comprehensive equivalent rebound modulus of the existing road reflects the whole bearing capacity of the road aiming at the cement concrete road surface, and the base layer and the lower equivalent rebound modulus caused by grouting are increased due to the defects of cracks and the like of the concrete slab, so that the whole bearing capacity of the road is not greatly changed, but the part below the base layer is reinforced, and the comprehensive equivalent rebound modulus of the road is only insufficient to be shown in the index of the road surface of the existing road. Obviously, by calculating the comprehensive equivalent rebound modulus of the road surface of the existing road, the influence of the road surface damage on the result is ignored, and the result is inaccurate. Disclosure of Invention The invention aims to solve the technical problem that the accuracy of the evaluation result of the existing evaluation method is low. Therefore, the invention provides the method for evaluating the grouting reinforcement effect of the cement concrete pavement, which can effectively improve the accuracy of the evaluation result. The technical scheme adopted by the invention for solving the technical problems is that the method for evaluating the grouting reinf