One-hole multi-pore-water-pressure-gauge burying structure and method

Abstract

The invention discloses a one-hole multi-pore-water-pressure-gauge burying method. According to the one-hole multi-pore-water-pressure-gauge burying method, embedded pipes with the diameter smaller than that of a drilled hole or a buried sleeve pipe at a preset position of a soil layer to be measured are arranged in advance, water holes are formed in the side wall of each embedded pipe, pore waterpressure gauges are arranged in the embedded pipes, and the embedded pipes are filled with fine sand; the sealed embedded pore water pressure gauges simulating the soil layers are formed, the embedded pipes are placed at preset positions, the outer layers of the embedded pipes are filled with clay, so that hole seal layers are formed, and then fine sand is used for filling; and then burying of the multiple pore water pressure gauges at different depths is completed. In this way, the situation that since soil conditions may change greatly, an obtained testing result cannot accurately reflect the pore water pressure change law at different depths within the same vertical plane can be effectively avoided, it is effectively avoided that the pore water pressure gauges vertically communicate, it is guaranteed that water seepage of a sand cushion around a probe of each pore water pressure gauge is fluent, the changes of the pore water pressures at different depths show obvious difference, and the testing result is accurate.

Description

technical field [0001] The invention belongs to the technical field of civil engineering construction, and in particular relates to an embedding structure and embedding method of a multi-hole porous water pressure gauge. Background technique [0002] Pore ​​water pressure is one of the frequently observed items in geotechnical engineering construction and research, and the pore water pressure gauge is a special instrument for testing the pore water pressure in saturated soil. However, different pore water piezometer burying and hole sealing methods will have a greater impact on the pore water pressure test results. The key technology is to ensure the smooth seepage of the sand cushion around the pore water piezometer probe, followed by cutting off the upper part of the borehole. Leakage downwards prevents up-down communication between pore pressure gauges. In principle, one pore water piezometer is buried in one borehole, but the disadvantage is that the distance between th...

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Problems solved by technology

In principle, one pore water piezometer is buried in one borehole, but the disadvantage is that the distance between the pore water piezometers at different depths on the plane varies greatly, and the test results obtained cannot accurately reflect the pore water pressure changes at different depths in the same vertical plane law

When choosing the burying method of a multi-hole pore water piezometer, it is difficult to seal the hole and bury the pore water piezometer by adopting the traditional method of pulling out the casing and collapsing the hole. The upper and lower pore piezometers are easily connected, and the pore water pressure values ​​at different depths are almost the same. The error of the test result is large

When the pore water piezometer is actually buried on the construction site, the buoyancy of the mud water in the borehole is often too large, and the speed of lowering the pore piezometer is slow, and even cannot be lowered to the predetermined burial depth. If it is emptied, it will easily lead to hole collapse

Although some technicians have improved the burying method of the pore water pressure gauge, the process is often complicated in the specific operation process, and the cost will be increased if special equipment is required

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