Pullout test device of ribbed bar in earth-rock dam rockfill material and test method thereof

Abstract

The invention relates to a pullout test device of a ribbed bar in an earth-rock dam rockfill material and a test method thereof. The pullout test device is provided with a measuring device and a horizontal pullout force applying system and comprises a motor, a speed regulating reducer and a threaded pull rod, wherein a test chamber is arranged in a testing direction, and a rockfill material and a wrapped ribbed bar are placed in the test chamber; symmetrical round holes which can be penetrated by the ribbed bar are formed in the two side walls, and one side of the two side walls is a pullout end; a loading plate is arranged vertical to the horizontal pullout force direction, and a normal loading system is arranged on the loading plate; a pullout force reaction frame is arranged between the pullout end of the test chamber and the measuring device; fixed connection is realized by virtue of a fastening bolt, and a pullout force counter force is provided; and the measuring device is connected with a to-be-tested ribbed bar by virtue of a pullout force and displacement sensor and one ribbed bar sleeve. The pullout test device provided by the invention can be used for solving the problem that normal pressure provided by the traditional pullout test device is too low and the problem of rigid connection between the ribbed bars with different diameters and a pull rod and also can be used for solving the problems of plugging the round holes and keeping the ribbed bars horizontal.

Description

technical field [0001] The invention relates to an indoor pull-out test device, which belongs to the field of geotechnical engineering. The device is mainly used in the indoor pull-out test of ribbed steel bars in rockfill materials of earth-rock dams. The invention also relates to a testing method for such a testing device. Background technique [0002] More than 90% of the dams that have been built or are under construction in China are earth-rock dams. The construction experience of high earth-rock dams and a large number of survey data show that when subjected to seismic loads, due to the "whip tip effect", the seismic acceleration and The permanent deformation is significantly larger than other parts of the dam, which may cause the instability of the dam and affect the safety of the dam. Reinforcement is an effective anti-seismic reinforcement measure for the dam crest, which has been successfully used in the 21.2-m-high Concoyerac dam in France, the 125.5-m-high Jelle...

AI Technical Summary

Problems solved by technology

First of all, the reinforcement position of the ribbed steel bar is usually more than 1 / 3 of the height of the earth-rock dam, so the overlying pressure of the reinforced body at the bottom layer of the high earth-rock dam above 300m can reach 2 Mpa, and the pressure provided by the traditional pull-out test device Secondly, the rockfill material is coarse-grained soil, and the rockfill material must be compacted with high-strength vibration in the test chamber to make it reach the maximum dry density. In order to avoid damage to other parts of the test device, the test chamber should be designed as detachable body

Finally, the ribbed steel bars in the test should be kept horizontal throughout the filling process, and the rigid connection between the ribbed bars of different diameters and the tie rods can be easily and rigidly connected, which cannot be achieved by the traditional pull-out test device

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