13 results about "Falling weight deflectometer" patented technology

The present invention relates to the technical field of road engineering, and provides a deflection basin parameter determination method and apparatus, a road testing device, a medium and a product. The method comprises: by means of a ground penetrating radar, acquiring a real-time deflection basin evaluation index value of any point in a road segment to be tested; and inputting the real-time deflection basin evaluation index value into a deflection basin parameter prediction model, to obtain a predicted deflection basin parameter value, wherein the deflection basin parameter prediction model is obtained by performing training on the basis of at least one deflection basin parameter value and a deflection basin evaluation index value which correspond to a reference point in a reference road segment, the at least one deflection basin parameter value is determined by means of a falling weight deflectometer, and the deflection basin evaluation index value is determined by the ground penetrating radar. In the present invention, a deflection basin parameter can be predicted simply by obtaining a real-time deflection basin evaluation index value by a ground penetrating radar, thereby improving the efficiency of deflection basin parameter determination.

A drop hammer deflectometer for pavement detection belongs to the technical field of pavement detection equipment and comprises a guide rod, a bearing plate and a heavy hammer, the bearing plate is arranged at the bottom end of the guide rod, the heavy hammer is slidably sleeved on the guide rod, a positioning disc is mounted at the top end of the heavy hammer, and the area of the upper surface of the positioning disc is smaller than that of the lower surface of the positioning disc. Compared with a traditional single-point bearing mode, the counter weight bearing device can carry out circumferential equidistant multi-point bearing on the counter weight, can avoid relative inclination caused by single-point bearing of the counter weight on the guide rod, and avoids friction caused by the inclination angle generated by the counter weight and the guide rod, so that the service life of the counter weight is prolonged, and the service life of the counter weight is prolonged. The heavy hammer can normally and freely fall along the guide rod in the subsequent road surface detection link, the accuracy of the road surface detection result is ensured, in addition, the supporting blocks do not need to be driven one by one to rotate, the four groups of supporting blocks are linked at the same time, and locking positioning or locking positioning removal of the heavy hammer is quicker and more convenient.

The application relates to the technical field of data error correction, in particular to a calibration error correction method and system of a drop hammer type deflectometer, which comprises the following steps: obtaining deflection values of a displacement sensor of the drop hammer type deflectometer to form a deflection time sequence, calculating deflection abnormal values of each deflection value, obtaining each deflection right sequence of each deflection value, further obtaining deflection continuation characteristic values of each deflection value, obtaining load transfer weights of each deflection value through the correlation degree between local deflection sequences of the same bit sequence deflection value in adjacent deflection time sequences, obtaining road loose influence degrees of each deflection value in combination with the deflection continuation characteristic values of the corresponding deflection values, further obtaining deflection vibration characteristic values of each deflection value and smoothing window scales of each deflection value, and performing smoothing treatment on each deflection time sequence to correct deflection data errors of the drop hammer type deflectometer. The application can improve the calibration error correction precision of the drop hammer type deflectometer.

This invention discloses a numerical simulation method for the maintenance and construction of semi-flexible pavement based on dual-scale coupling, comprising: determining the dimensions of the milled and repaved section based on the original pavement structure obtained by three-dimensional ground-penetrating radar and falling-weight deflectometer; establishing a finite element model for the original pavement structure; simulating the semi-flexible layer after milling and repaving using discrete element method and coupling it into the finite element model to construct a dual-scale coupled model; performing simulation calculations on the compaction and molding of large-void parent asphalt mixture; conducting simulation derivation of self-leveling cement slurry filling based on the construction process and the dual-scale coupled model; establishing a discrete element numerical model for cement curing to characterize cement curing behavior; and evaluating and guiding the maintenance of the semi-flexible pavement based on the dual-scale coupled model. This invention realizes process control and performance evaluation during the construction period of semi-flexible pavement and guidance for maintenance and repair during service life, making up for the shortcomings of high testing costs and insufficient theoretical data for different construction conditions in semi-flexible pavement.

This invention relates to the field of roadbed strength, specifically to a method for detecting the strength of highway roadbeds based on a semi-empirical modified curve. This invention records the pressure and displacement during impact using sensors on a falling weight deflectometer, calculates the vertical displacement of the road surface, selects a Beckman beam deflectometer and a test vehicle, installs the Beckman beam deflectometer between the two rear wheels of the test vehicle, corrects the test vehicle parameters, calculates the deflection value, corrects the diameter of the left and right tires of the test vehicle to 22.35 cm, and corrects the ground pressure of the left and right tires of the test vehicle to 0.75 MPa. The vertical displacement and deflection values ​​measured in steps (2) and (3) are recorded and compared with the national highway roadbed strength standard, thereby achieving rapid detection of roadbed strength without damaging the road structure. Furthermore, the test vehicle can be used to detect and evaluate the road smoothness of the selected road.

A system for evaluating the strength improvement of the roadbed through bamboo fiber reinforcement, consisting of: a) a material processing unit for producing a soil-bamboo fiber mixture, wherein the bamboo fibers are selected from the group consisting of Barak (Bambusa balcooa), Bari (Bambusa polymorpha), and Mritinga (Bambusa tulda), wherein the fibers have a length of 1.5 cm and a diameter of 2-3 mm and are incorporated at a rate of 3% of the dry weight of the soil; b) a compaction test facility configured to perform the Standard Proctor compaction test to determine the maximum dry density (MDD) and optimal moisture content (OMC); c) a load-bearing capacity test unit configured to perform CBR (California Bearing Ratio) tests, wherein the test unit is designed for CBR tests in both the impregnated and unimpregnated states; d) a subgrade preparation unit configured to prepare a subgrade test section for roadways, comprising layering and compacting the soil-bamboo fiber mixture in 150 mm thick layers to achieve a subgrade thickness of approximately 600 mm; and e) a deflection measuring unit for performing a falling weight deflectometer (FWD) test, wherein the deflection measuring unit comprises seven geophone sensors arranged at intervals of 0 mm, 300 mm, 600 mm, 900 mm, 1200 mm, 1500 mm and 1800 mm from the center of a load plate, and a load cell configured to apply a load of 40 kN.

The application relates to a pavement nondestructive detection device and method based on a ground penetrating radar and a deflectometer, and belongs to the technical field of pavement nondestructive detection. The detection device comprises a mobile base, a ground penetrating radar for acquiring pavement detection data, a drop hammer deflectometer for acquiring a deflection basin index at a pavement disease position, and a marking structure for marking the pavement disease position. One pavement disease type corresponds to one mark. A controller comprises an information receiving module for receiving the detection data and the deflection basin index, a judgment module for determining the pavement disease position and the corresponding pavement disease type and determining the pavement disease degree, a position acquiring module for acquiring the current position of the drop hammer deflectometer in real time, and a control module for controlling the drop hammer deflectometer to act when the current position matches the pavement disease position and for controlling the marking structure to act after the pavement disease position is determined. The application has the beneficial effect of reducing the core drilling verification step.

The invention belongs to the crossing field of road engineering technology and artificial intelligence, and particularly relates to a road structure modulus back calculation method based on a large model and reinforcement learning. Analyzing and extracting structured parameters by a large language model, and generating initial modulus estimation driven by engineering knowledge; constructing a forward mechanical model based on a two-dimensional axisymmetric finite element, and calculating a theoretical deflection basin; designing a composite reward function, and driving a reinforcement learning agent to iteratively adjust the modulus of each structural layer; and in the optimization process, a large language model is periodically called to provide optimization direction guidance, and local optimum is prevented. Compared with a traditional back calculation method, the method has the advantages that the convergence rate is 100% on a synthetic data set, and the average deflection error is 1.69 + / -0.69%; the method supports adaptive processing of various road surface types such as flexible road surfaces, semi-rigid base layers and atypical structures, and has high robustness and engineering practicability.

This utility model relates to the technical field of vehicle-mounted falling weight deflectometers and discloses a vehicle-mounted falling weight deflectometer, including a support frame. An automatic detection and cleaning mechanism is provided on the outer side of the support frame. The automatic detection and cleaning mechanism includes a movable storage platform. Two hydraulic cylinders are fixedly connected to the outer surface of the support frame, and the extension end of each hydraulic cylinder is fixedly connected to the outer surface of the movable storage platform. The outer surface of the movable storage platform is slidably connected to the interior of the support frame. This vehicle-mounted falling weight deflectometer, by incorporating the automatic detection and cleaning mechanism, can automatically detect and clean impurities on the outer surface of the falling weight. Simultaneously, it can precisely adjust the height and overall weight of the falling weight according to experimental requirements, not only improving the applicability of the device but also enhancing the accuracy of the experiments. It effectively prevents impurities from adhering to the surface of the falling weight, affecting the depth of subsequent falling weight experiments, and thus reducing the effectiveness of the device.

The evaluation method for the grouting reinforcement effect of the cement concrete pavement of the present application comprises: before grouting: S1.1, setting multiple test points in the evaluation section; S1.2, collecting deflection basin data of each test point by using a falling weight deflectometer; S1.3, calculating the comprehensive equivalent resilient modulus E of the test points before grouting Fi ; S1.4, correcting the comprehensive equivalent resilient modulus E Fi , to obtain a corrected value E F . After grouting: S2.1, collecting deflection basin data of each test point by using a falling weight deflectometer; S2.2, calculating the comprehensive equivalent resilient modulus E of the test points after grouting Bi ; S2.3, correcting the comprehensive equivalent resilient modulus E Bi , to obtain a corrected value E B . Evaluation: S3, outputting the evaluation result of the grouting reinforcement effect according to the corrected values E F and E B . The evaluation method of the present application can effectively improve the accuracy of the evaluation result.

The invention relates to the technical field of road engineering nondestructive testing and state evaluation, in particular to a three-dimensional GPR-FWD integrated rapid diagnosis method and system for concealed diseases of a frozen soil road. The method comprises the following steps: synchronously acquiring pavement-base course-roadbed body data and a multi-base-distance deflection sequence of a road to be measured; an electromagnetic forward modeling library is called to generate a three-dimensional slice template, template matching is carried out, and disease categories, geometric scale parameters of diseases and similarity scores are output; carrying out power inversion of the drop weight deflectometer, and outputting the layer thickness and the equivalent modulus; performing calculation based on the multi-base-distance deflection sequence, and outputting a plurality of condition indexes; performing composite end point grading, and outputting disease grades and corresponding treatment suggestions; and generating a diagnosis report. The GPR map interpretation ambiguity is reduced, the layered modulus inversion accuracy is improved, a diagnosis-grading-disposal engineering closed loop is realized, the hidden disease discovery and disposal efficiency and accuracy can be remarkably improved, and the method has wide industrial application value.

The invention relates to the technical field of bearing performance evaluation, and particularly discloses a large-gap asphalt mixture pavement bearing performance evaluation and acceptance inspection method which comprises the following steps: S1, temporarily forming a flat interface transition layer on the surface of a pavement to eliminate the influence of surface gaps; s2, carrying out a loading test on the interface through a drop weight deflectometer, recording load and displacement data, generating a first deformation curve, and calculating a theoretical bearing capacity according to the first deformation curve; s3, the same loading test is carried out on the surfaces of the adjacent original large gaps, a second deformation curve is generated, and the actual bearing capacity is obtained; s4, calculating the ratio of the theoretical bearing capacity to the actual bearing capacity, and comparing the ratio with a preset threshold value to judge whether the bearing capacity of the road surface is qualified or not; according to the method, by comparing the test results of the ideal state and the actual state, quantitative evaluation of load transmission efficiency reduction caused by gaps of the large-gap pavement is realized.

The application provides a laser deflection instrument measurement result correction method based on a finite element model, and belongs to the technical field of measurement instrument measurement result correction, which comprises the following steps: constructing a viscoelastic pavement model; calculating a deflection parameter measurement value Y of the laser deflection instrument on the viscoelastic pavement model; calculating a standard deflection parameter measurement value Y0 of a falling weight deflectometer on the viscoelastic pavement model; calculating deflection correction parameters ρ under the action of various environmental factors through the deflection parameter measurement value Y and the standard deflection parameter measurement value Y0; screening out m environmental condition influence factors which have a greater influence on the measurement result of the laser deflection instrument; establishing a laser deflection instrument measurement result correction model; and correcting the measurement result of the laser deflection instrument according to the laser deflection instrument measurement result correction model. The measurement result of the laser deflection instrument is corrected, the accuracy of the measurement result of the laser deflection instrument is improved, and it is ensured that the measurement result does not affect the accuracy of subsequent modulus back calculation.