In many years of underground engineering since the waterproof concrete structure, due to the construction quality problems, there is a general phenomenon of seepage, not only affects the normal use of the building, but also to the construction enterprise to bring maintenance difficulties.

　　In accordance with China's underground building waterproofing system engineering project construction and acceptance of work specification management provisions, the construction joints of wall panels should be left in the enterprise higher than the surface of the bottom plate to carry out not less than 200mm of the wall, and in the wall panels of concrete in the form of steps, concave, convex and pre-embedded metal plates. In this problem area began to appear a leakage of the main part of the reason is: construction system although in raising the concrete wall panels to stay in the construction joints, but in the actual construction joints in the steps of the existence of the impact of the concrete is not dense layer, or other surfaces between the surface did not we chiseled carefully, the existence of such a number of isolation layer; there are concave joints groove as a result of being subjected to the process of supporting the molding of the upper wall panels may be dropped into the garbage, although this high-pressure Water gun flushing, there is still the development of a significant portion of the fine particles can be composed of a thin layer of garbage retained in the groove, reducing the wallboard's impermeability; for students to form a kind of concave-convex form of the existence of construction joints in the form of templates, when the study of the concrete has not yet been able to achieve a certain strength of their own in a hurry to dismantle the mold, will result in concave-convex joints localized cracking, loosening or prying damage, and damage to the community after the analysis of the information technology is not dealt with; in the The use of pre-buried metal plate construction joints, the joints are not welded, or lap length is relatively short; on the design of the side columns and exterior wall panels as a single structure, the construction of construction joints in the wall and columns are not continuous, the appearance of columns and walls at the point of discontinuity; installation of the wall as a template in the construction joints part of the seal is not tight, the completion of the process of concrete pouring found that construction joints at the spread of the cement mortar leakage of slurry is serious, the pouring was not Timely take... Reliable measures were taken to effectively prevent commercial concrete from segregating, resulting in stone piles.

　　In response to the above construction defects, the horizontal construction joints left on the concrete wall panels should be selected as convex joints, and the height of the construction joints left on the wall panels above the bottom slab surface should meet the requirements specified in the specification as well as be considered from the design point of view. If a floor beam perpendicular to the wallboard is set on the local plate, the height of the construction joint on the wallboard should be set above the elevation of the top of the beam; at the intersection of the wall and the column, the gap of the column hoop reinforcement can be utilized to keep the convex joints continuous; when the strength of the concrete in the convex joints completely reaches the strength without missing corners, the formwork on both sides of the convex joints can be removed. For the damaged convex joint area, some concrete can be chiseled out from the wall panel to re-form the convex joint. Before installing the upper wall panel formwork, the uncompacted concrete at the convex joint step should be chiseled out until there are no small holes in the visual inspection; at the same time, the protruding part of the convex joint should be chiseled out, the surface floating slurry layer should be removed, and the tightness and firmness of the sealing formwork at the construction joints should be carefully checked. The thickness of the cement mortar should be laid to cover the projecting joints, and the length of the mortar should be compatible with the pouring speed of the concrete, and should not be too long or intermittent leakage. When the height of concrete discharged in the wall panel exceeds 3m, a flexible chute can be used for pouring according to the thickness of the wall panel to avoid segregation of concrete.

　　U-shaped prestressed concrete sheet pile is a new type of precast pile developed by Shanghai Sinotech Pile Industry Co., Ltd. for three years, which changes the shortcomings of traditional engineering materials, such as high cost, poor stress performance, inconvenient construction, unstable molding quality, etc., and is more... , beautiful, economical, and simple maintenance in the later stage. At present, U-shaped sheet piles have been successfully applied in the domestic river improvement, waterway upgrading, landscape shoreline and other projects, which well meets the dual needs of technology river policy. With the U-shaped sheet pile in the water conservancy project construction vigorously promote, it will be in our country's rivers, seas, lakes, reservoirs, sluices and other places to set up an indestructible, century-old "Great Wall on the water".