7 Ground Anchor
7.1 The structure of ground anchors shall be designed based on the loading conditions and the geological conditions in the site where lifting operations are performed.
7.2 Each ground anchor shall be numbered,and shall,based on the load-bearing point,have a corresponding coordinate shown in the plot plan for lifting operations.Additionally,each ground anchor shall be buried and backfilled to ensure its location and direction are in compliance with the requirements of design documents.
7.3 There shall not be any trench,cable,underground piping,etc.in front of the ground anchor foundation pit,i.e.,within the radius of 2.5 times the pit depth in the loading direction of the guy rope.
7.4 Ground anchors shall be fabricated and set up in accordance with the lifting method statement.Embedded ground anchors shall be backfilled with clean soil which shall be tamped or compacted layer by layer to a height above the ground surrounding the ground anchor foundation pit.Meanwhile,records of concealed works shall be well maintained.
7.5 Upon completion of ground anchor setup,the guy rope shall be pre-tensioned with a tensile force not less than 100kN.
7.6 Main ground anchors shall be tagged with allowable tensile force,and shall not be overloaded.
7.7 Within the radius of 2.5 times the depth of ground anchor foundation pit around the area where ground anchors are buried,neither trenching nor soaking shall be allowed.
7.8 In mountain regions,if ground anchors are located at the front faces of the mountains,they shall be arranged in small flat lands,either natural or artificial ones.
7.9 In soft soil regions,socket type ground anchor with counterweight may be used.Both the socket type steel structure and counterweight of the ground anchor shall be designed and fabricated according to the maximum tensile force carried through the ground anchor,and shall comply with the following requirements:
a)The socket type steel structure shall be firmly attached to the ground;
b)The counterweight shall be placed properly and firmly in accordance with the method statement;
c)No lateral tensile force shall be applied.
7.10 A dynamometer should be provided on the guy rope of the main ground anchor for observation of both force variation and stability of the ground anchor.