Pile soil interface shear simulation tester of opened concrete pipe pile

Abstract

The invention belongs to the technical field of testing equipment of buildings and relates to a pile soil interface shear simulation tester of an opened concrete pipe pile, wherein a screw rod is vertically installed on an operation platform, an upper end and a lower end of a spring are respectively fixed on a dismountable spring upper fixation plate and a dismountable spring lower fixation plate, a testing soil sample is placed inside an upper shear box, the top part is flush with the dismountable spring lower fixation plate, and the left side face of the upper shear box is rigidly connected to the operation platform; a concrete sample is placed inside the lower shear box, a slide track is disposed on the operation platform, the operation platform is connected to the lower shear box by a roller, and a numerical control motor is rigidly connected to the lower shear box; and a vertical displacement sensor is installed on the dismountable spring lower fixation plate, a horizontal displacement sensor is installed between the upper shear box and the lower shear box, and a load sensor is placed on a first steel rod on the left side of the upper shear box. The pile soil interface shear simulation tester of the opened concrete pipe pile has a simple structure, is operated conveniently, has scientific theories, obtains accurate testing results, has low cost and is applied widely.

Description

Technical field: [0001] The invention belongs to the technical field of test equipment for construction, and relates to an open concrete pipe pile pile-soil interface shear simulation test device. Background technique: [0002] At present, open concrete pipe piles have become one of the most important pile types in my country, and are widely used in the construction of industrial and civil buildings, port projects, and water conservancy projects. During the process of penetrating the foundation soil of open concrete pipe piles, Part of the soil is extruded into the pile hole to form a soil plug. The bearing capacity provided by the soil plug is an important part of the vertical compressive bearing capacity of the open concrete pipe pile, and the bearing capacity at the end of the soil plug is completely provided by the frictional resistance between the inner wall of the pile and the soil plug. Now the traditional field and model tests encounter the following problems in the ...

AI Technical Summary

Problems solved by technology

Now the traditional field and model tests encounter the following problems in the process of studying the load transfer mechanism of open concrete pipe piles: First, the bearing capacity of soil on open concrete pipe piles is gradually in the order of outer resistance-pipe wall end resistance-inner resistance The resistance on the inside and outside of the pile wall is not synchronized, and the traditional load transfer model of pile foundation is no longer applicable. Second, because the inner wall of the concrete pipe pile is rough and easy to wear, and the pile hole is completely different from the surrounding pile. The existing load transfer theory function can no longer accurately describe the load transfer characteristics inside the pile wall; during the pile sinking process of open concrete pipe piles, due to the soil plug effect, the soil will be strongly compressed and expanded. The normal stress of the pile-soil contact surface changes greatly, but the normal stiffness of the soil remains basically unchanged. This type of soil cannot be tested for shear strength with the traditional direct shear instrument, and the traditional direct shear instrument cannot be used during the shearing process. The shear area decreases continuously, and the size effect is more obvious, which affects the test results

Images