Multi-functional digital seismic wave hole pressure static sounding testing system

Abstract

The invention provides a multi-functional digital seismic wave hole pressure static sounding testing system. The multi-functional digital seismic wave hole pressure static sounding testing system comprises a cone head (1), a hole pressure filter ring (2), a side wall friction barrel (3), an adapter (4), a connecting rod (5), a friction reduction rod (6), a probing rod (7), an upper computer data acquisition circuit board (8), a depth encoder (9), a data acquisition computer (10) and a coaxial cable (11), wherein the coaxial cable (11) penetrates through the friction reduction rod (6) and the probing rod (7); one end of the coaxial cable is connected with two power lines and two signal lines in the connecting rod (5); and the other end of the coaxial cable is connected with the upper computer data acquisition circuit board (8). The multi-functional digital seismic wave hole pressure static sounding testing system is compact and reasonable in structure, reliable in circuit design, high in testing precision, convenient to use, high in measurement efficiency, accurate and reliable in measurement result and good in repeatability, and provides a powerful testing tool for civil engineering exploration practice.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering testing, in particular to a method for evaluating underground soil engineering properties and acquiring engineering design parameters, and in particular to a novel multi-functional digital seismic wave piezostatic penetrating test system. Background technique [0002] The static penetration technology has a history of more than 80 years. It refers to the use of a pressure device to press a penetration rod with a contact probe into the test soil layer, and to test the penetration resistance and side wall friction of the soil through the measurement system. Determine some basic physical and mechanical properties of soil, such as soil deformation modulus, soil allowable bearing capacity, etc. The static penetrating sounding has been widely used in the world, partially or completely replacing the drilling and sampling in the engineering survey. In 1965, our country first successfully developed...

AI Technical Summary

Problems solved by technology

During the penetration process, the underground soil easily enters these gaps, which reduces the activity of the side wall friction cylinder and hinders the transmission of side wall friction resistance. the accuracy of the measurement results

In addition, in engineering practice, the side wall friction resistance is generally small, and it is not easy to be directly detected by the side wall friction resistance strain gauge, resulting in insufficient accuracy of the measurement results, especially in soft soils

[0004] 2. The domestic pore pressure static penetrating test system, whether it uses analog signals or digital signals, its data acquisition system is very backward, and its structural design is not strict

In the data acquisition system using analog signals, the signals interfere with each other seriously, resulting in inaccurate measurement results

The data acquisition system adopts digital signals. On the one hand, the power supply and arrangement of the cone tip resistance strain gauges and side wall friction strain gauges on the deformation column are unreasonable, and the signals are not stable, which reduces the reliability of the test results; On the one hand, the existing acquisition system directly transmits the collected digital signals to the acquisition software of the upper computer through the cable. When the data transmission fails or the signal is wrong during the test process, it cannot accurately identify these wrong signals. It is easy to collect wrong data during the test

[0005] 3. The depth measurement method of the domestic pore pressure static penetrating test system is backward, the main reason is that manual reading, rack and pinion combination or photoelectric encoder reading are generally used

However, the survey of complex projects requires shear wave velocity within a smaller depth range. When using a single three-component geophone, it is necessary to stop the measurement at each point to be tested, which is laborious and time-consuming, and is not conducive to improving the efficiency of engineering surveys.

[0007] To sum up, there are flaws in the probe structure of domestic and foreign pore pressure static penetration test systems, and the data acquisition system is backward, which not only reduces the accuracy of the penetration test results, but also increases the test cost

However, foreign pore pressure probes are expensive and difficult to repair after failure, which is not conducive to domestic promotion and application.

Images