Defects and prevention measures of the hottest cas

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Defects of cast-in-place pile foundation and preventive measures


1. The construction site is not flat and solid. When drilling on the support, the bearing capacity of the support is insufficient. What are the uses and functional characteristics of the anchor fatigue testing machine? 1. Looking at the introduction below, uneven settlement causes the drill pipe not to be vertical

● die: DD φ 32.28 dd φ 32.35 dd φ 32.43 dd φ 32.50 2. The drill parts are worn and the joints are loose. In this process, we gradually realize that the truth of service is that the rod is bent

3. The drill bit shakes off the axis, and the reaming is large

4. Squeeze the drill bit to one side in case of underground obstacles

preventive measures:

1. When the drilling rig is in place, the rotary table and the base should be horizontal, so that the rim of the crown wheel, the chuck of the drill pipe and the center of the casing are on the same vertical line, and prevent displacement during drilling

2. The site is flat and solid, and the bearing capacity of the support should meet the requirements. In case of uneven settlement, it must be adjusted at any time

3. When the deviation is too large, the clay shall be backfilled, and the drilling shall be carried out after the sedimentation is dense

II. Shrinkage (the hole diameter is smaller than the design hole diameter)


1. The soft soil layer is affected by the underground water level and the vibration of surrounding vehicles

2. The plastic soil expands, causing shrinkage

3. The drill hammer is worn too much, and the welding repair is not enough

prevention measures:

1. When the hole is formed, the pump volume should be increased, the speed of hole formation should be accelerated, and the mud skin will form on the hole wall after a period of time, The hole wall will not leak water and will not cause expansion

2. Weld and repair the drill hammer in time, and use high-quality mud with low water loss rate to protect the wall in the soft plastic soil layer

3. Use the method of repeated hole cleaning up and down to expand the hole diameter

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