Transmission line pole and tower hollow-square type pile anchor composite foundation suitable for karst region and construction method thereof

Abstract

The invention relates to a foundation scheme of a transmission line pole and tower under the karstic feature, in particular to a transmission line pole and tower hollow-square type pile anchor composite foundation suitable for a karst region and a construction method thereof. The center is a pile foundation, an anchor rod foundation mounted on the periphery of the pile foundation and a plate typesteel reinforcement cage located in the middle of the pile foundation and containing a surrounding pile foundation are arranged on the periphery, a hollow-square structure is formed on a section, theplate type steel reinforcement cage is a connecting body of the pile foundation and anchor rods, and meanwhile serves as a bearing platform, through concrete pouring, the pile foundation and the platetype anchor rod foundation are connected to form a whole body, and bearing force is provided for the pile foundation. When the foundation is applied to the fact that on the transmission line karst region, in the pile foundation excavating process, during meeting a substrate large karst cave, the pile foundation and the plate type anchor rod composite foundation can be organically combined, comprehensive up-pull / down-press bearing force is improved, the side effect of the karst geology on transmission line building can be effectively solved, it is ensured that the foundation stress meets the bearing force needs, a karst cave does not need to be avoided, the construction period is ensured, and the construction investment is reduced.

Description

technical field [0001] The invention relates to a foundation scheme for transmission line towers under karst terrain, in particular to a return-type pile-anchor composite foundation for line poles and towers suitable for karst areas and a construction method thereof. Background technique [0002] Karst is an area with cave geology that lies beneath layers of rock at unpredictable heights. In the preliminary survey process of line construction in karst areas, drilling surveys can only survey the distribution of strata at a local point, and cannot cover a geological change in the entire tower position, and geophysical prospecting methods for karst surveys also have many limitations and cannot be accurately judged Karst development in this area. [0003] The excavated pile foundation is a common foundation type in mountainous areas of transmission lines, and its buried depth is generally 6-15m. However, if the bottom of the excavated pile encounters a karst cave, the mechanica...

AI Technical Summary

Problems solved by technology

In the preliminary survey process of line construction in karst areas, drilling surveys can only survey the distribution of strata at a local point, and cannot cover a geological change in the entire tower position, and geophysical prospecting methods for karst surveys also have many limitations and cannot be accurately judged Karst development in the area

[0003] The excavated pile foundation is a common foundation type in mountainous areas of transmission lines, and its buried depth is generally 6-15m. However, if the bottom of the excavated pile encounters a karst cave, the mechanical performance of the pile end will be reduced, which often cannot meet the bearing capacity. Therefore, when encountering karst caves, two solutions are generally adopted: one is to use rubble grouting to fill the karst caves, but since the volume of the karst caves cannot be estimated, the investment is large, laborious and time-consuming, and it is difficult to be widely used; In the way of karst caves, it is necessary to change the design plan, increase a large amount of investment, and extend the construction period

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