Combined with the actual construction situation on site, it is proposed to take the measures of blocking, draining and plugging to ensure the smooth progress of the construction during the flood season. Drainage: carry out ground hardening, drainage ditch and water collecting well construction around the foundation pit to ensure that the rainwater can be discharged in time; Blocking: block the opening of the first support plate to prevent the rainwater on the first sealing plate from flowing into the foundation pit; leakage prevention: Strengthen the monitoring of foundation pits, and deal with leaking parts in a timely manner.

1. Drainage during rainy season and measures to prevent foundation pit irrigation

a. In order to prevent a large amount of surface water, groundwater, etc. from infiltrating the foundation pit, causing the foundation pit to be flooded, destroying the stability of the slope, and affecting the construction progress, measures must be taken to combine ground water interception and drainage in the pit. Before it rains, clean the sump and drainage ditch in the pit, prepare submersible pumps and other pumping tools, and organize manpower and material resources in time to carry out the pumping and drainage work in the pit and the dredging work around the foundation pit after it rains.

b. For several days of rain or heavy rain, it is necessary to take effective water-retaining and drainage measures on the ground to prevent a large amount of rain from pouring into the foundation pit. The foundation pit is drained by a submersible pump, and the drain pipe should be equipped with a sufficient length to drain the water out of the construction site.

c. The overall plan of the planning site

During the rainy season, the construction is based on "prevention first", the general layout of the site is reasonably planned, and measures combining rain protection and enhanced drainage are adopted. Ensure the normal operation of construction and production during the rainy season, and minimize the impact of seasonal weather on the construction of the project. Before the rainy season, the overall drainage system of the construction site should be improved, drainage ditches and water collection wells should be set up reasonably, and drainage outlets should be cleaned to ensure smooth drainage.

Plan the scope of responsibility of each flood control and emergency rescue team on the site master plan. The junction of each team should overlap. If there is a problem at the junction, both teams have responsibilities.

d. Increase the frequency of groundwater level observation, keep abreast of changes in groundwater level and take corresponding technical measures.

2. Strengthen foundation pit monitoring during rainy season

a. Mainly monitor the following aspects: whether there are cracks or depressions in the concrete on the top of the retaining wall; whether there is deformation or cracks and displacement of the retaining wall shotcrete; whether there is water accumulation and displacement at the foot of the retaining wall.

b. Observation should be patrolled regularly every day, and records should be made. If there is any danger, it should be reported to the foreman in charge immediately, and the construction work under the retaining wall should be stopped. If the drainage ditch outside the roof is damaged or blocked, it should be repaired and dredged immediately, and the accumulated water at the foot of the retaining wall should be dredged immediately.

c. During the whole construction process, the cracking and deformation of adjacent ground surfaces and objects should be continuously observed. Under normal circumstances, the occurrence of small cracks on the surface can be regarded as normal, but the development trend must be closely tracked and special treatment measures must be taken in time. When the cracks appear to develop and extend continuously, the original construction process must be stopped, the support parameters must be modified and reinforced in time.

d. During the construction process, when the ratio of the lateral displacement of the top of the foundation pit to the excavation depth at that time exceeds 1‰ (or exceeds the designed displacement of the retaining wall), the observation should be closely observed and the supporting measures should be taken in time, if necessary, increase the Use other support methods.

3. Rainproof measures for the opening of the first floor and the driveway

a. Construction in the rainy season with the post-casting zone: In order to effectively protect the steel bars at the post-casting zone from corrosion, and prevent the rainwater collected on the roof from flowing into the basement during the rain, before the rainy season, 240*240mm bricks were built on both sides of the first-layer post-casting zone. The wall retaining platform is set with a concrete cover plate for sealing, and the joints between the prefabricated plates are filled and smoothed with cement mortar.

b. The tower crane position of the first floor slab and the reserved hole for rainy season construction: construction joints should be left at the first floor slab construction to the tower crane position, and the remaining slabs can be constructed after the tower crane is removed. Before the rainy season, a 120*240mm high brick wall water retaining platform was built around the lattice column supporting the tower crane, and the open-air opening was covered with color strips on the water retaining platform to prevent rainwater from flowing into the basement along the plate hole around the tower crane. ;Equipment hoisting reserve a 240*240mm brick wall water retaining table around the opening. Because the opening is too large, the upper steel pipe is covered with color strips and then compacted with bricks to prevent the rainstorm from directly falling and damaging the covering facilities and entering the basement in large numbers.

c. Construction of stairs and pipes on the first floor in the rainy season: There are a large number of openings in the first floor that cannot be closed. In order to prevent a large amount of rainwater from entering the basement in the rainy season, rainproof measures should be taken for the stairs and pipes out of the first floor. Stairs and pipes that have been constructed should be covered with colored strips of cloth. For stairs and pipes that have not been constructed, a 120*240mm high brick wall water retaining platform should be built around them, and the larger openings should be covered with colored strips of cloth.

d. Construction of car and bicycle ramps on the first floor in the rainy season: Before the rainy season, the car and bicycle ramps on the first floor should be connected with drainage hoses at the bottom of the drains at the top and bottom of each slope, and the other end of the drainage hose should pass through The ground drains on the underground floors near this location are reserved, and finally penetrate into the basement water collection well to collect rainwater into the water collection well.