From April 1, 2023, it is known in the industry as the "strictest waterproof new regulations".General Code for Waterproofing in Construction and Municipal Engineering GB55030-2022Start implementation. It stipulates that the working life of the waterproof design of underground engineering should not be less than the working life of the engineering structure design, and puts forward higher requirements for the waterproofing measures of the main structure and joints of underground engineering. Based on the new waterproof regulations, this article summarizes the joints of underground engineering structures"Three seams and one belt": construction joints, deformation joints, post-pouring belts, and induction joints, how to construct them?
The General Code for Waterproofing of Construction and Municipal Engineering GB55030-2022 clearly states that the overall requirement of "three seams and one belt" for the joints of underground engineering structures by the cut-and-cover method is to ensure the continuous sealing of nodes, improve the reliability of waterproofing through multi-channel fortification, and the waterproof fortification measures should comply with the provisions of the following table:
1. Construction joint structure: The construction joint is the joint between the joints between the concrete poured successively due to the need for sectional pouring due to the design or construction needs to be poured in sections. For underground engineering, the bottom plate should try not to set up construction joints, but the side wall construction joints are unavoidable, and the position of construction joints should be set at the place where the structural stress is small and convenient for construction.
Based on the specification, the horizontal construction joints of the side walls of underground engineering are mostly waterproof steel plate waterstops and waterproof expansion waterstops, or a combination of the two, and the weak links are provided with a reinforcing layer along the joints. 
Horizontal construction joint structure of side wall 2 deformation joint structure.
Deformation joints are structural joints that are left to prevent the deformation of buildings under the action of external factors, including expansion joints, settlement joints and shockproof joints. Underground projects without deformation and obvious settlement should be provided with less or no deformation joints, and construction measures such as post-pouring belt or warehouse jumping method should be adopted as much as possible.
Based on the specification, the deformation joint should be fortified in multiple ways to meet the deformation requirements, and on the basis of the buried medium-hole rubber waterstop, a flexible waterproof membrane should be set on the surface of the water, and the waterproof surface should be sealed and waterproof and a protective layer should be set up.
The purpose of the deformation joint structure 3 post-pouring belt structure is to prevent cracks in the concrete structure under the action of factors such as ambient temperature (temperature post-pouring belt), self-shrinkage (shrinkage post-pouring belt), and uneven settlement (post-settlement pouring belt).
Based on the specification, the post-pouring belt should be arranged at the place where the mechanism is less stressed, and the compensating shrinkage concrete is poured, and the strength grade and impermeability grade should be higher than the concrete on both sides, the steel bar at the post-pouring belt shall not be disconnected, and the water-stopping steel plate waterstop or the water-swelling water-stop strip in the middle is usually set up, and the additional waterproof layer is set on the water surface.
The bottom plate is post-poured with a structure
Side wall post-pouring belt construction
Roof post-pouring belt structure.
The bottom plate is ahead of the water stop and the post-pouring belt structure is constructed, and the 4 induced joints are constructed.
The induced joint is to prevent irregular cracks in the ultra-long concrete structure engineering, and the joints are set at the appropriate position of the wall panel to meet the requirements of effective guidance and cracking without leakage, and the irregular cracks are guided to the specified parts, and the induced joints can be combined with the deformation joints.
Based on the specification, one or two inducers are set up in the induction joint based on the thickness of the wallboard, and the waterproof measures are strengthened by sealing waterproof materials and external waterstops on the basis of the embedded waterstop, so as to control the cracking of the induction joint position without leakage.
Induce seam structure The flavor will become stronger in 2024