Testing system of external pressure resistance of lining steel pipe of water tunnel

Abstract

The invention discloses a testing system of external pressure resistance of a lining steel pipe of a water tunnel. The system comprises a steel sleeve and a blocking end cover, wherein a testing steelpipe is tightly connected with the steel sleeve via the blocking end cover; a cavity body is formed between the testing steel pipe and the steel sleeve; water injection ports and drainage ports are formed in the steel sleeve; the water injection ports are connected with a booster pump via water inlet pipes; the booster pump is controlled by boost control equipment; a deformation monitoring sensoris mounted on an inner wall of the testing steel pipe; a data wire of the deformation monitoring sensor is led out to a data acquisition system; the testing system is characterized in that the testing system comprises buttresses; the steel sleeve is horizontally placed on the buttresses; and support wheels for supporting the testing steel pipes are arranged at the low-half part of an inner wall of the steel sleeve. The system can determine critical outer buckling water pressure of the lining steel pipe on the premise of ensuring safety and trueness and without on-site testing, and optimization design requirements of the lining steel pipe of the water tunnel are met.

Description

technical field [0001] The invention belongs to the technical field of construction, and in particular relates to a test system for the external pressure resistance performance of a steel pipe lined in a water delivery tunnel. Background technique [0002] The water conveyance tunnel is an underground structural system built in rock (soil) and is an important part of water diversion projects. At present, multi-layer lining is often used. Generally speaking, it includes: outer lining such as shotcrete , segments, etc.; linings such as steel pipes, PVC pipes, etc.; reinforced concrete, self-compacting concrete, etc. filled between the outer lining and the inner lining. During the long-term service of the water tunnel, the cracking of the outer lining and filling layer will cause groundwater from the outer rock (soil) to seep inward to the outer wall of the inner steel pipe, so that the pressure of the outer water directly acts on the inner steel pipe, which will easily lead to...

AI Technical Summary

Problems solved by technology

[0008] Although the above-mentioned model test scheme is relatively simple to operate, it has the following defects: (1) The model test object is a scaled steel pipe prepared according to a geometric similarity ratio, which is significantly affected by size effects and boundary effects, especially the aspect ratio ( The ratio of specimen length to diameter) is too small, resulting in differences between the model test results and the real buckling resistance of the prototype steel pipe

(2) The devices are all vertically loaded, and the external water pressure on the test steel pipe is simplified to a uniform radial distribution, which is inconsistent with the distribution pattern of the actual external water pressure with a vertical gradient

This method needs to test the test steel pipes of the completed water delivery tunnel on the actual project site. Although the test object is a real full-scale structure, the safety risk is high and the operation is difficult: the gates at both ends need to be specially designed, and the construction The site is located underground, so it is very inconvenient to lift and install; at the same time, in order to ensure that the water delivery tunnel can continue to be used in the later stage, it is necessary to avoid obvious damage to the steel pipe during the test process, and it cannot be carried out to the destruction stage

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