Construction process for rock enlarged toe anchor pile foundation of overhead power transmission line

Abstract

The invention discloses a construction process for a rock enlarged toe anchor pile foundation of an overhead power transmission line. The construction process comprises the following steps of: (1) measuring and positioning, namely measuring a tower foot position and removing a rock surface to determine a foundation bolt base point; (2) drilling, namely drilling a straight hole at the base point by using a tubular drill until the drilling is finished, and enlarging the bottom of the straight hole by replacing a deviation bit to form a taper hole, wherein the aperture and the depth of the straight hole are determined according to the external diameter and the length of an anchor rod; the taper angle is controlled by controlling the drill bit sinking and the deviation speed; the lower bottom surface of the taper hole is coincided with the bottom of the straight hole; the taper height is determined according to the actual demand; the taper hole is coaxial with the straight hole; the upper bottom of the taper hole is the section of the straight hole; the diameter of the straight hole is 8 to 10cm more than the external diameter of the anchor rod; and the taper angle is 30 to 40 degrees; (3) placing an anchor and grouting, namely placing the anchor rod into the hole to insert a foundation nut and a part of rod body into the taper hole and grouting a CGM30 grout into the hole until the grout reaches the rim of the hole, wherein the anchor rod and the straight hole are coaxial; and (4) pouring a bearing platform, namely pouring the anchor rod which is exposed out of the straight hole into the bearing platform by using high-standard cement, wherein the foundation nut and a foundation bolt are protruded out of the surface of the bearing platform.

Description

Technical field [0001] The invention relates to a rock anchor pile foundation technique for an overhead power transmission line, and specifically discloses a construction technique for an overhead power transmission line rock anchor pile foundation. Background technique [0002] The traditional rock anchor pile foundation technology for overhead power transmission lines is mainly aimed at fixing the tower feet of overhead power transmission lines in mountainous areas on unweathered, lightly weathered or moderately weathered rocks. Vertical drilling is often used. Hole type, lower anchor rods are reinforced with fine stone and cement mixture, and a concrete bearing platform with an area not less than the width of the tower foot slab is built on the rock surface, so that the anchor rod and anchor bolts are formed by the mixture of fine stone and cement and the hardness of the rock Anchor pile with high pull resistance. The utility model with the patent number: ZL200820014059.6 dis...

AI Technical Summary

Problems solved by technology

However, no matter it is the vertical anchor foundation or the combination of vertical and inclined anchor foundation technology, there are some shortcomings, that is, the construction time is long, the consumables are large, and the distance between the anchor piles for fixing the tower foot plate is small. , the vertical anchor will greatly reduce the pullout resistance of the rock under the same pile foot, and the application range of the vertical and inclined anchor pile foundation in mountainous areas will also be limited by the geographical environment

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