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.