Design and Features of Xiamen Jidang Lake Drainage Pumping Station

Abstract: The design flood control standard for the large-scale pumping station of Jidang Lake in Xiamen is once in 50 years. The pumping station scale is 40 m3 / s. In this paper, the engineering design of the pumping station, the use of pumping station set up gravity system, the implementation of the tide, water exchange and other characteristics were introduced. Key words: flood discharge; pumping station; engineering design CLC: TU992.25 Document code: C Article ID: 1000-4602 (2000) 11-0035-02 Xiamen Datang Lake Pump Station is a The lake basin is mainly flood control and flood discharge, and also has a large drainage pumping station to improve the exchange capacity of water between the Lixintang Lake and the West Sea. The total investment is about 75 million yuan. 1, pumping station location selection After many programs, the site selected in the West when the West Side of the southern end of the sewage treatment plant south, is conducive to drainage to the west. Pumping station to avoid the lake when the water level, the retention of the integrity of the lake shoreline will not affect the entire staff when the lake landscape, but also with the original drainage gate at the northern tip of the implementation of the tide into the lake, invigorate the water body. In addition, the pump station installed capacity, use less time, full load less running time. Site located in the sewage treatment plant next to the pump station can be used to change the power distribution equipment to the sewage treatment plant unified power supply, centralized management, reduce project investment and operating costs, give full play to the comprehensive economic benefits of the pumping station. 2. Standards and scale of pumping station flood control When the flood control and drainage facilities of the lake take the principle of "taking both vent and bank into account, taking discharge as the main principle", in addition to maintaining the floodgates of Dangdang Lake and giving full play to the flood discharge function of the drainage gate in the north end of the Xidi, Flood discharge pumping station, you can focus on stormwater runoff discharge into the sea, from the top of the tide impact, while conducive to the rational design, the controller when the lake elevation. According to the master plan of the city, the design catchment area of ​​Jidang Lake is about 35km2 and the flood storage area of ​​the lake is about 1.6km2. The standard of flood control is 50 years (p = 2%), the water level from -0.7 to -1m, the maximum water level + 1m, pumping station size 40m3 / s. 3, pumping station design pumping station project by the water tank culverts, collectors, pump houses, since passage, high wells and water tank culverts and other structures, from east to west was arranged in a word. 3.1 Intake tank culvert Pumping station inlet is located at the southern end of the West Lake outside the lake when the staff is Dangdang and West Lake and West Lake Road. The total length of the inlet culvert is 80m. The cross-sectional form is as follows: the middle section is a rectangular section (44m × 22m) with 5-hole rectangular box culvert with a net area of ​​4m × 2m per hole; trapezoidal bell mouths at both ends, Width from 22m to 30.5m, in order to control the water flow rate, a diversion wall is added in the middle of each rectangular box culvert to form a 10-hole trapezoidal box culvert with a net area of ​​2.7m × 2m per hole; Wide from 22 m to 35.5m, the same 10-hole trapezoidal culvert, a net area of ​​3.2m × 2m per hole. In order to prevent large suspended solids and garbage in the water from entering the pump house, 10 man-made slag-purifying iron grills and wells with a length of 6m and a width of 35.5m at the inlet of the water collecting pond are provided. Each grille is 2.5m × 6m deep 4.5m, grid fence tilt angle of 60 °, the wellhead set up steel railings. The water inlet culvert is of reinforced concrete structure. The elevation of the floor surface is -3m. The elevation of the roof surface is -0.6m (the elevation of the lakeside west road surface elevation is +2 m. The ground elevation of the Xidi River is + 4.5m.) The depth of the culvert is 2.6-5.1m. When the lake elevation of the lake -2.5m, 15m in the inlet of the lake bottom, with a block stone paved slope-type buffer inlet. 3.2 The east side of the sump pool is connected with the trapezoidal section of the grid section of the water intake culvert, which is 11.5m long and widened from 35.5m to 42.5m. The west side is connected with the water pump house in a rectangular section with a length of 33.5m , Width 42.5m, the elevation of the bottom of the pool -4.5m, the elevation of the top of the pool + 1.5m, and the pool volume of about 11200m 3, which receives exchange water bodies from the Jidang Lake and the west sea area. The south and north sides of the pool are reinforced concrete upright arch walls, and the bottom of the pool is dry masonry stone surface on the coarse sand cushion. In addition to the west of the pool, the remaining three sides along the shore masonry railing and stone pathways planted around the turf slope protection, with green isolation belt with the pumping station outdoor ground connection. 3.3 pump room pump size 8.7m × 45.6m, the underground part of the deep 9.3m, divided into two floors, the ground part of a layer. The lower part of the pump house, elevation of the floor surface -4.5m, the middle of the free-flow passage 13.2m wide, west of the pump chamber on both sides, a total of nine sets of Swedish ABS submersible axial flow pump, of which 14.6m wide south (layout 4 ), 17.8m wide on the north side (5 units arranged) and 2m × 2.9m × 6m pump chamber. There are 9 diversion walls between the pump chambers, each pump flow is 4.26 ~ 5.04m3 / s and the lift is 2.5 ~ 6.5 m, motor power 318kW, the total installed capacity of 2862kW. In the middle of the pumping station, the elevation of the floor is + 1.5m. In the middle, a partition wall is set up from south to north. The warehouse is on the east side and there are 9 workshops on the west side. DN1600 pipe is about 12m long . Single-well single-row high-pit way, the pipeline laying inclination angle of 12.1 °, depth 2.3 ~ 4.3m, the outlet pipe through the double flange through the wall into the high wells, in order to prevent the sea water intrusion, outlet nozzle set back to the door. Pump room on the upper floor, floor elevation +4.8 m, 9m high, for the pump maintenance room for non-flood season pump maintenance, maintenance and storage of the use of maintenance set up a weight of 10t bridge crane. 3.4 Self-flow passage The gravity passage passes through the middle of the lower part of the pump house with a plane dimension of 17.7m x 13.2m and an elevation of the bottom plate of -4.5m. The eastern section is located below the pumping station and is 8.7m long. In the channel, three rows of 12 columns with a diameter of 600mm are arranged in the width direction to form four channels of 3.3m in width. The middle of the runway, floor elevation + 3.5m, corridor for the cable laying. The upper floor, floor elevation + 5.7m, 6.1m high, between the transformer and low voltage distribution room. 3.5 High Wells Wells are reinforced concrete structures with a flat size of 6.8m × 43.7m and nine outlet pipes arranged on both sides of the north and south sides. The elevation of the floor surface is -2.7 m on both north and south sides, the middle is -3.2 m and the elevation of the roof is 5.1 m Both sides of the roof around the three steel pipe railing. Four (2.5m × 3.0m) electrohydraulic gates are provided on the east side (14m wide) of the upper wells and the gravity flow passage, and the western (20.3m wide) , Set 6 (2.5m × 2.5m) electric hydraulic gate. In order to facilitate the cleaning and maintenance of pump room and gate, 4 (2.5m × 9.1m) and 6 (2.5m × 7.8m) steel folding rectangular frames are provided at 1.4m outside of the hydraulic gate on the east and west sides respectively gate. The middle of the upper well, the plane size of 11.8m × 20.3m, floor elevation +5.1 m, 6m high, for the gate operation and hydraulic stations, operating on both sides of each supporting the establishment of a 3t manual monorail crane for lifting two Side-fold beam rectangular gate. 3.6 Outlet tank culvert The total length of the water tank culvert is 340m with a bottom width of 20.3m and a range of 250m from the west to the sea mouth. The upper part is the site for the development of the Xidi Pier. The cross-section is 6-hole rectangular box culvert with a net area of ​​3m × 2m per hole. Water tank culvert for the reinforced concrete structure, floor elevation -2.7m, roof elevation -0.3m, box culvert buried depth of about 4.8m. The estuary is 12.5m from the revetment line in the west sea area. The retaining walls on both sides and the revetment line are connected into a bell-shaped bell mouth to control the water flow speed into the sea mouth. 4 Design Features ① The pump station has 9 submersible axial flow pumps, 10 hydraulic gates and 9 large beading doors and other major machinery and equipment, all of which are imported from Swedish ABS Company. Although the cost of introducing foreign equipment is relatively high, in the long-term interest, the life, material, sealing and reliability of imported equipment have greater advantages and have achieved more advantages in terms of operation, maintenance and energy saving Good overall economic efficiency. ② pump room to set up a gravity passage, with the implementation of the West Bank embankment gate when the lake tide, water exchange. In the lower part of the pump room set up four self-flow channel, channel mouth set 4-hole gate, every day when the ebb tide, open the gravity gate, the water can flow into the sea. After calculation, 4 channels, an ebb cycle displacement of about 80 × 104m3. Usually when the lake when the lake needs to raise the water level, the floodgate can be used to control the gate timing, water diversion. After completion of flood discharge pumping station, the use of gravity flow channel increases the exchange of water between the lake and the West China Sea, so that when the lake water quality and Lake District environment has been further improved. ③ Make full use of pumping station underground structure, rational layout of the ground building. Pumping station land 1.64hm2, outside the Xidi seaside, the layout of the pump maintenance room, power distribution room and gate operation room concentrated in the pump room, gravity channel and the upper wells of the upper floor, the comprehensive building built on the west side of the water tank culvert Above, make full use of the basis of these structures and reinforced concrete walls, saving land, saving construction costs. The façade shape of the ground building, focusing on the overall architecture and simplicity, interspersed with several different geometric shapes, the effect is bright and full of sculpture, architectural style as far as possible with the coastal environment landscape coordination. The rational arrangement of ground structures saves the cost of basic treatment, freeing up ample open space in limited areas for fountains, golf courses and tree planting to make the pumping station a garden-style public building.