A two-way layered shear model box device and its application method

Abstract

The invention discloses a two-way layered shear model box device and its use method. The device includes a U-shaped layer frame, a rolling body system, a limit device and an inner liner bag. The U-shaped layer frames are vertically and equidistantly arranged in parallel. Through the interlayer rolling body system connection, the limit device is used to limit the plane torsion and vertical vibration deformation of the U-shaped frame, and the bottom frame is fixed on the vibration table. The use method includes a. assembling the rolling body system; b. assembling the model box body and fixing it on the vibrating table; c. assembling the limit device; d. laying a liner bag inside the box body and adding soil in the box body And embed the model structure; e. Vibrate in one direction; f. When the direction of vibration changes, switch the rolling bearing platform from along the direction of vibration to the direction perpendicular to the vibration, and continue the vibration test in the other direction. The invention can vibrate in two directions, has small self-weight, adjustable rigidity, simple operation, wear-resisting and durable, firm structure, and can repeat one-dimensional or two-dimensional shaking table tests.

Description

technical field [0001] The invention relates to the technical field of geotechnical engineering, in particular to a two-way layered shear model box device and a method for using the same. Background technique [0002] Under the action of an earthquake, the response of the semi-infinite natural soil layer overlying the rigid bedrock is similar to that of a shear beam under the action of vertically propagating shear stress, and the lateral deformation is approximately sinusoidal. In the shaking table model test, Prototype foundations can only be simulated approximately within a container (model box) of limited size. Due to the fluctuation reflection on the container boundary and the change of the vibration form of the system, the model test results are different from the seismic response results of the natural soil layer, that is, the "model box effect". Therefore, a good model box design should minimize the interference of boundary conditions, so that the model foundation ca...

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Problems solved by technology

[0004] my country's "Code for Seismic Design of Buildings" clearly stipulates that for irregular underground structures, it is advisable to calculate the horizontal and vertical horizontal seismic actions of the structure at the same time, but according to the relevant test results of the layered shear model box, most of these tests only input one direction The seismic excitation of the subway station structure is analyzed on the basis of the plane assumption, and the spatial effect of the seismic response of the complex underground structure is not considered

There are also some layered shear model box devices for shaking table tests. Although earthquake excitation can be performed in two directions perpendicular to each other, when the model box is input with earthquake vibration in another direction, the balls in the chute must be reinstalled. , the operation process is more cumbersome and laborious

In addition, the balls installed between the upper and lower frames of the traditional model box are severely worn under the overloaded frame pressure and dynamic load, and the overall shear deformation of the model box is difficult to achieve an ideal state. As a result, the vibration test is difficult to simulate the soil due to the lack of accuracy of the test data. The actual stress state and whether the ball system between the frame layers can work normally will directly determine whether the model box equipment can be reused, thereby reducing unnecessary waste of manpower and material resources.

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