The foundation pit is a soil pit excavated at the foundation design position according to the foundation elevation and foundation plane size.
Foundation pit engineering mainly includes the design and construction of foundation pit support system and earthwork excavation. It is a highly comprehensive system engineering. It requires close cooperation between geotechnical and structural engineering technicians. The foundation pit support system is a temporary structure, which is no longer needed after the completion of the underground engineering construction.
Definition of deep foundation pit: The Ministry of Construction Jianzhi No. 200987 on the issuance of the “Notice on the Safety Management Measures for Sub-item Projects with More Dangerous Sub-item Projects” stipulates that: general deep foundation pit refers to the excavation depth exceeding 5 meters (including 5 meters) Or the basement has more than three floors (including three floors), or although the depth does not exceed 5 meters, but the geological conditions and surrounding environment and underground pipelines are particularly complicated.
In addition, the foundation pit and the foundation trench are both used to build the foundation of the building, but the plane shape is different. The foundation pit is square or closer to the square; the foundation trench is elongated and sometimes longer. You want What is mastered is the difference in their shapes.
A foundation pit refers to a foundation pit with a bottom area of less than 27 square meters (not 20), and the bottom long side is less than three times the short side.
The base groove refers to the base groove with the width of the groove bottom within 3 meters and the groove length greater than 3 times the groove width.
In other words, the general definition of a deep foundation pit is: the bottom area is within 27 square meters (not 20), the bottom long side is less than three times the short side, and the excavation depth exceeds 5 meters (including 5 meters) or the basement is more than three floors ( (Including three floors), or the depth is not more than 5 meters, but the geological conditions and surrounding environment and underground pipelines are particularly complicated. (On the contrary, shallow foundation pit)