Technical disclosure of the latest manual hole digging pile
The manual hole digging pile shall be excavated in the way of "skip one dig one". During excavation, the height of each section in the soil layer is generally 1m. In case of fine sand and silty sand layer geology and light quicksand, the method adopted is to shorten the excavation depth of this cycle, and shorten the normal section of 1m to 0.5m, so as to reduce the exposure time of the hole wall in the excavation layer, and carry out wall protection concrete pouring in a timely manner, Reinforcing bars above φ 18 shall be driven into the sand layer every 100mm or so along the perimeter of the retaining wall, or straw mats shall be stuffed into the retaining wall reinforcement. In case of severe quicksand, lower the steel sleeve. The steel sleeve is similar to the steel template used for wall protection. With the outer diameter of the hole as the diameter, it is divided into 4 to 6 segments of arc, plus appropriate ribs, and connected with each other by bolts or steel ring buckles. After about 0.5m of excavation, the sleeve can be installed in pieces. The depth of the sleeve into the hole bottom is not less than 0.2m, and it is inserted into the outer side of the upper concrete wall protection, After installation, the formwork shall be erected and the retaining wall concrete shall be poured. When encountering soft soil layer such as muddy soil layer, support with timbers, wooden formwork, etc., shorten the excavation depth of this section, and timely pour concrete retaining wall. The timbers for support shall be driven into the bottom along the periphery not less than 0.2m deep, and the upper part shall be embedded behind the poured concrete retaining wall of the upper section. During excavation, simple tools such as pick and shovel with short handle shall be used. When encountering hard rock, air pick can be used and winch shall be used to transport soil vertically. When the pile hole is dug deep, use the low-voltage lamp of rubber cable for lighting. After a section is excavated, it shall be reported to the on-site technicians and quality personnel for inspection after the self inspection is qualified. When the hole is below 10m, harmful gas detection must be carried out every morning before the hole is lowered, and the hole can be lowered only after it is qualified.