A large hollow cylinder sample maker for coarse-grained soil and its use method

Abstract

The invention discloses a large-sized hollow cylindrical sampler for coarse grained soil and a use method thereof. The sampler comprises an annular sleeve and a vibrating compacter, two parts in all, wherein the annular sleeve comprises an annular base (1), an annular outer sleeve (2), an annular inner sleeve (3) and an annular extension barrel (4); and the vibrating compacter comprises a vibrating motor (7), a circular iron plate (12), a dowel bar (6), a positioner (8) and an annular iron plate (5). While using the instrument, a soil sample (9) is paved at first and then put into the annulariron plate (5); next, the vibrating motor (7) is turned on; when the edge of the annular outer sleeve (2) is level with the positioner (8), the vibrating motor (7) stops vibration and the next layer of soil sample (9) is added; and then vibration compaction is performed until the soil samples reach a predetermined height. The sampler is simple to use, convenient for operation and control, and capable of preparing a highly compact and even test sample, so that the time and labour for preparing the test sample are saved.

Description

technical field [0001] The invention relates to the technical field of civil and water conservancy engineering tests, in particular to a coarse-grained soil large-scale hollow cylinder sample preparation device and a use method. Background technique [0002] High earth-rockfill dams will have catastrophic consequences once they fail due to the high water capacity of the dams. Therefore, it is necessary to carry out research on the dynamic characteristics of dam materials. Under the action of earthquake load, the internal stress state of the high earth-rockfill dam is relatively complex. The conventional dynamic triaxial test can only simulate the simple stress loading path, but cannot realize the complex stress loading path and the rotation of the principal stress axis. The hollow torsional shear instrument is considered to be a better test equipment for simulating soil dynamic stress loading because it can carry out three-way unequal pressure loading during the test. For ...

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Problems solved by technology

[0003] Before the present invention, "Patent: A Hollow Cylindrical Torsional Shear Instrument Remodeling Compactor (Application No.: 200710164847.3)" disclosed a remodeling compactor, which uses a free-falling hammer The kinetic energy provided is for compaction, and the energy is small (the mass of the compaction hammer is 2.835kg). To increase the compaction energy, it is necessary to increase the weight of the compaction hammer and the length of the guide rod, which undoubtedly increases the difficulty of sample preparation during the test , laborious and time-consuming; the uniformity of each layer is difficult to control

It is mainly suitable for reshaping small and medium-sized hollow cylindrical samples, and it cannot be compacted for large-scale hollow cylindrical samples with coarse grains (such as the outer diameter of the sample is 500mm, and the inner diameter is 300mm), and it cannot solve the problem of sample preparation when the relative density of coarse-grained soil is relatively high. Difficult, unable to solve the problem that the sample is difficult to form when the relative density of the coarse aggregate is low

[0004] The patent "A Hollow Cylindrical Sample Preparation Apparatus (Application No.: 200920228846)" discloses a hollow cylindrical sample preparation apparatus. During the use of the device, the test sample is evenly placed on the pressure plate and the hollow cylinder to form In the embedded space, the sample is compacted by turning the handle, without considering the instability of the sample itself after the preparation is completed, so it is only suitable for remodeling samples, not suitable for the preparation of coarse-grained soil samples

[0005] In addition, during the sample preparation process, due to the increase in the size of the sample, the friction between the annular inner sleeve and the rubber film inside the sample material increases, and it is difficult to disassemble with the conventional split mold or three-split mold design. inner sleeve

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