In-hole double-plunger water injection infiltration testing apparatus and working method thereof

Abstract

The invention discloses an in-hole double-plunger water injection infiltration testing apparatus and a working method thereof. The testing apparatus comprises an upper water stop cavity, a water injection testing cavity and a lower water stop cavity which are sequentially and coaxially connected, wherein each of the upper water stop cavity and the lower water stop cavity comprises a steel tube anda swelling air bag sleeving the outer side of the steel tube; the water injection testing cavity comprises a water permeable patterned tube and a water injection cavity filter net mesh sleeving the outer side of the water permeable patterned tube; a plurality of through holes are formed in the side wall of the water permeable patterned tube. The in-hole double-plunger water injection infiltrationtesting apparatus has the advantages as follows: the test cost is reduced; the test can be performed on soil layers at different depths in one hole; the testing apparatus can be repeatedly used, water is separated through air pressure expansion, the one-time input cost with the adoption of PVC pipes is reduced, besides, the cost for water separation through a waterstop or mud balls outside a casing pipe is reduced, and the cost is saved.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, in particular to an in-hole double plunger water injection penetration tester and a working method thereof. Background technique [0002] Hydrological parameter testing is an indispensable and important part of hydrogeological and engineering geological exploration work. Whether the permeability of groundwater in the soil layer can be accurately tested in the process of exploration and testing, and the relevant parameters of hydrogeology can be determined. , foundation construction, etc. play an important role. [0003] At present, there is no special test instrument for measuring the permeability coefficient of groundwater in the borehole. The test method widely used in the project is to drill on-site, put a water injection pipe (PVC pipe or steel pipe) in the hole, and set up a penetration test section. The non-test section is water-blocked by expansive mud balls or waterstops...

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Problems solved by technology

[0004] The main difficulty of the existing method for measuring the permeability coefficient of the soil layer in the hole is that: it is necessary to drill and wash holes specially for the test, and the test is not conducive to combining with the drilling in the survey process; the test device needs to be specially made of water-injected steel pipes or PVC pipes, It is unfavorable to cost control and environmental protection; the test device needs to use mud balls or waterstops for water isolation, which is difficult for non-test soil layers; after the test, the PVC pipe is left in the hole, which has certain engineering risks; the test device is installed Complicated, the whole test takes a long time and requires a lot of investment, which is not conducive to the on-site test

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