Upper arch effect demonstrating instrument

Abstract

The invention discloses a soil arching effect demonstrator. There is a half cylindrical rubber airbag in the center of the bottom of Perspex box. Outside the airbag there is flexible rubber membrane. They are fixed at the bottom of Perspex box. From bottom to top, the Perspex box is filled with yellow sand and black sand; tube of the airbag is connected with inflatable bag outside the Perspex box; in the tube of inflatable bag, there is release valve and forward one-way valve; there is one backward one-way valve in the inflatable bag. By giving air and releasing air, the soil arching can be directly observed.

Description

technical field

[0001] The invention relates to an experimental device, in particular to a soil arch effect demonstrator. Background technique

[0002] Soil (such as sand) is a kind of granular material. Theoretically speaking, this kind of granular material needs certain support to be stable, such as the lining of underground tunnels and the support of foundation pits. However, in practice there are situations in which parts or all of the soil can remain stable without support, such as animal burrows. This is due to the soil arching effect. Due to the soil arching effect, the vertical earth pressure acting on the tunnel lining is often less than the self-weight stress of the overlying soil layer. The soil arching effect also affects the measurement of earth pressure in the field soil. The mechanism of the soil arch effect: In practice, there are often differences in the degree of support of various parts of the soil, and there is a relative sliding tendency between soil...

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