Concrete cast-in-place pile construction for Shanghai strong foundation: concrete cast-in-place pileHole formation is an important part of construction. If its quality is not well controlled, hole collapse, diameter reduction, pile hole deflection and pile end cannot meet the requirements of the designed bearing layer may occur, which will directly affect the pile quality and cause the decline of pile bearing capacity.
When the drill is in place, lay the steel plate, align the center line of the drill bit with the center of the pile hole, and control the error in2cmOr less. The lifting pulley of the rotary drill and the clamping machine of the fixed drill pipe are located in the same vertical line to keep the drill pipe vertical. When drilling, drill at low speed and under the guard1mThen drill at normal speed. Pay attention to keep a certain amount of mud in the guard cylinder before drilling, each rig is equipped with two sets of mud pump rotation, often check the slurry discharge system, accelerate mud circulation.
During the construction, pay attention to the uniform lifting and dropping bits to avoid hitting the hole wall; Take reliable measures when connecting and unloading drill pipe to prevent the bit from falling off; After the drill pipe is removed, check and clean, grease and maintain. In the process of drilling, the mud consistency in the hole should be kept proper and the water level stable. According to the seepage and deficiency of the mud in the hole, the mud should be added in time to maintain the water head difference in the hole and prevent the hole from collapsing. Sample THE BALLAST at ANY time, check the design geological data in time, and adopt the corresponding drilling parameters and mud consistency according to the formation changes. In the process of drilling, the depth and inclination of drilling are often measured to find problems and deal with them in time.
In the drilling process, different soil layers are used with different rates of penetration, weight on bit, mud specific gravity and mud volume. In the soil layer such as sand and soft soil, which is easy to collapse the hole, the low-grade slow drilling is adopted, and the water head in the hole is raised at the same time, and the proportion of mud is increased to prevent hole collapse. For the sand layer, in order to prevent hole collapse or wide hole, can fill the hole with clay block, repeatedly lift the drop, so that the clay squeezed into the hole wall to a certain depth,Fastening hole wall.
If THE geological conditions at the bottom of the hole are not consistent with the design after the hole is formed, it shall be reported to the design, supervision and other units to study and determine the treatment method.
Shanghai Qiangqiang Foundation Engineering Co., LTD. 's business covers foundation pit engineering, pile foundation engineering, land and waterFoundation treatment , slope treatment and other engineering fields. Around"Excellent technology, reliable process ", construction fast "technical requirements,Is to provide customers with land, water foundation engineering technical consultation, construction services and other comprehensive solutions of the entity enterprise.Contact Number:400-1002850
