Automatic acquisition and control system of borehole shear test data

Abstract

The invention discloses an automatic acquisition and control system of borehole shear test data. The automatic collection and control system comprises a data acquisition system for acquiring shear stress of a shear head and converting the shear stress into a digital signal, an automatic control system for receiving the digital signal and applying the digital signal to a motor control signal, and amotor driving system for driving the shear head to shear according to the control signal. The data acquisition system comprises a pressure sensor, a signal processing module and a data acquisition module which are connected in series successively, the motor driving system comprises a motor and a motor driving module for controlling the motor rotational speed, a data output end of the data acquisition module is connected with a data input end of the automatic control system, a control signal output end of the automatic control system is connected with a signal input end of the motor driving module, and a signal output end of the motor driving module is connected with a driving end of the motor. The automatic acquisition and control system provided by the invention is simple in operation, stable in working performance and high in test success rate; the number of personnel and labor intensity for test are reduced, and the test efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of geotechnical performance data acquisition, and in particular relates to an automatic acquisition and control system for drilling shear test data. Background technique [0002] Borehole Shear Test (BST for short) is an in-situ test method for obtaining soil cohesion and internal friction angle by performing a shear test on the side wall of a pre-drilled hole, which can be applied to pile foundation bearing Force, slope, retaining wall, deep foundation pit design and landslide geological survey and other projects. [0003] Compared with the indoor direct shear test, the borehole shear test is directly carried out in the on-site borehole, which avoids the disturbance of the test soil. For the saturated clay, silt and sand that are difficult to sample, drilling The advantage of the hole shear test is more obvious. Therefore, the borehole shear test is favored by professional geotechnical engineers and resea...

AI Technical Summary

Problems solved by technology

[0004] Existing shear test equipment such as figure 1 As shown, the pressure is applied to the shearing head 3 through the gas tank 1 and the gas pipeline 2, and the shearing head is driven by the hand-operated turbine structure 4 to perform shearing. The pressure gauge 5 is used to display the shearing stress, and the shearing force is recorded manually. The degree of automation and intelligence of this equipment is low, and the main problems in the test process are as follows:

[0005] 1. The shear rate of the artificial hand crank is uneven, resulting in a low test success rate: the first-level pressure test requires one person to shake the handle continuously, and the speed must be kept at about 2 revolutions per second, a total of 400 to 800 revolutions, and the duration is 3 to 5 minutes. A total of 5 levels of pressure tests are required for each test point, which takes 30 to 60 minutes in total; due to the high labor intensity, often due to the fatigue of the test personnel, the unbalanced shear rate, and the impact damage to the test soil, the shear stress curve cannot appear peak, causing the test to fail

[0006] 2. The accuracy of data recording is not high, which affects the accuracy of the test: the shear stress during the test is displayed by the pointer pressure gauge, and one test recorder is required to record the shear stress, and the recording frequency is 2-5s / time; Continuously, the shear stress changes with time, the manual reading is difficult to be accurate, and there are often misreadings or under-readings

[0007] 3. The efficiency of data analysis and processing is low: After the field test is over, the test personnel need to process the test data, draw the shear stress and time related charts by hand or use excel and other software, calculate the shear parameter values, and organize the test results report, Heavy workload and low efficiency

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