A compressive static load test method for cast-in-situ piles

Abstract

The invention discloses a compressive static load test method of cast-in-situ piles. Including the following steps: (1) equipment preparation; (2) assembly of parallel combination jack; (3) fabrication of reinforcement cage; (4) welding of parallel combination jack and reinforcement cage; (6) Weld the anchor pile reaction device or install the surcharge reaction device on the ground; (7) Collect and analyze the test data according to the slow-speed maintenance load method in the "Technical Specifications for Testing of Building Foundation Pile". The mixed reaction force device designed by the present invention can use part of the invalid pile body to provide part of the reaction force, and the insufficient part can be provided by the anchor pile method or the surcharge method, thereby solving the problem of strict simulation due to the fact that the designed pile top is located underground and the surface site is narrow. The working conditions of engineering piles, the difficulty of digging deep foundation pits and other conditions, as well as the engineering problems that the existing static load test method is difficult to achieve the purpose of pile testing.

Description

technical field [0001] The invention relates to a compression test method for construction piles, in particular to a single pile compression static load test method suitable for urban rail transit cast-in-place pile test conditions, and belongs to the technical field of geotechnical engineering detection. Background technique [0002] For urban rail transit pile test projects, the design pile top elevation is usually about 20 meters underground and does not have the conditions for large-scale excavation. The design requires strict simulation of engineering pile conditions. To obtain the real pile top settlement, the ultimate bearing capacity of the pile needs to be converted, so the self-balancing method cannot strictly simulate the working conditions of engineering piles. However, the problems faced by traditional static load test methods such as anchor pile method, surcharge method or their combined methods are as follows: First, the pile top can only be led to the surface...

AI Technical Summary

Problems solved by technology

[0002] For urban rail transit pile test projects, the design pile top elevation is usually about 20 meters underground and does not have the conditions for large-scale excavation. The design requires strict simulation of engineering pile conditions. To obtain the real pile top settlement, the ultimate bearing capacity of the pile needs to be converted, so the self-balancing method cannot strictly simulate the working conditions of engineering piles

However, the problems faced by traditional static load test methods such as anchor pile method, surcharge method or their combined methods are as follows: First, the pile top can only be led to the surface without excavating the foundation pit, and the extended pile body will inflated the number of single piles. bearing capacity and pile settlement; secondly, if the inflated pile body is treated with anti-friction treatment, the upper pile body will inevitably be suspended in the air, causing stability problems during the loading process of the test pile

Therefore, the simple use of traditional static load test methods and self-balancing test methods cannot achieve reliable test purposes.

Therefore, to find a single pile compressive static load test method suitable for urban rail transit cast-in-place pile test pile conditions, to solve the problem that it is difficult to excavate deep foundation pits due to the fact that the designed pile top is located underground and the surface site is narrow, and strict simulation engineering is required. The static load test problem of pile condition is of great significance

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