Huayuankou breach is located on the south bank of the North Yellow River in Zhengzhou.In order to prevent Japanese troops from invading the west, the government of the Republic of China dug the Yellow River levee at Yuankou, Huahua, on June 9, 1938, causing the whole river to seize the river.The closure project of Huayuankou was started on March 1, 1946, closed on March 15, 1947, closed on April 20, and completed in May.
Chinese name
Closure of Huayuankou of the Yellow River
Foreign name
Levee closure of Huayuankou breach on Huanghe River
When the mouth is plugged, the mouth is 1460m wide, and the soil of the river bed above and below the mouth is all fine grain quicksand.There is about 1000m shoal at the west dam head of Koumen, the main stream is close to the east dam head, the channel is 460m wide, and the water depth is 1-5m in small water.On the eve of the closure, the measured discharge at the entrance in the winter of 1945 was 746 m3/s, the average flow rate was 1.21m/s, and the maximum water depth was 9 m.During the eight years of seizing the river, the old channel flows intermittently in case of rising water. The riverbed of the old channel has been silted up 2.67m within 50km, while the riverbed upstream of Koumen is brushed 2.3m deep. The water surface is 3m lower than the old channel in winter and spring when there is little water. Therefore, the water surface must be raised 4m when plugging to make the whole river return to the old channel.
Organization
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In February 1946, the Government of the Republic of China established the Huayuankou Closure and Dike Restoration Engineering Bureau. The director of the Bureau was concurrently the chairman of the Yellow River Water Resources Commission. The Bureau had public works, finance and accounting, materials, transportation and other departments, which were solely responsible for the construction;Henan Provincial Government has formed a recruitment and material purchasing committee, which is responsible for recruitment and material purchasing;The Ministry of Communications is responsible for building a special railway to Huayuankou via Guangwu Station of Pinghan Railway, and allocating motor transport trains: Henan Branch of the General Administration for Rehabilitation and Relief of the Executive Yuan is responsible for distributing relief materials, health care and medical care;The United Nations Relief and Rehabilitation Administration (UNRRA) sent consultants and technical teams to the construction site with a variety of mechanical equipment.More than 260 workers participated in the construction, including about 900 workers, and 50000 migrant workers from Shengduoshi.[1]
Plugging scheme
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As early as the second year of the breach, the relevant departments formulated the "Yellow River Closure Project Plan Draft".In 1942, the "Project Plan for Port Closure and Dike Restoration" was prepared. After that, experts were organized to discuss the port closure scheme for many times, and the port closure model test was carried out at Chongqing Hydraulic Experiment Department.In 1945, large-scale hydraulic model test was conducted in Longxi River, Changshou County, Sichuan Province.Finally, it was decided to adopt the scheme of bridge erection and riprap leveling.Considering that the old dike has been destroyed by years of war and eroded by wind and rain, and that there are more than 400000 people in the riverbed who are farming and living, it must be relocated. After negotiation, it is decided that the closure, dike restoration, and relocation must go hand in hand.
Main works of plugging
The main works of plugging include: ① Dongba.The head fascine (30m wide at the top, 20m long and 10m high) shall be wrapped in the head box of the east breakwater, and the water shall be occupied from the Xiangtou of the east dam. The east bridgehead dam (10m wide at the top, 40m long and 12m high) shall be used as the base for the blockage. As the old dike below the dam head is incomplete, a new section of the dike (20m wide and 1150m long) shall be repaired. ②Xiba.A section of the new embankment (20m wide at the top, 800m long and 8m high) will be built along the shoal from the end of the west embankment. A 60m long beach protection dam will be built every 150m near the river for the new embankment. The fascine will be built between the dams (10m wide and 355m long) for maintenance. The berm will be built on the back of the river. The new embankment will be wrapped firmly in the shallow water at the end of the new embankment and serve as the west end dam. ③Closure dam.At the deep water of the entrance, first use willow branches and soft grass to make firewood rows, which will be used as the bottom protection project for 400m.Press 0.5m crushed stone.Pile rows shall be driven at the downstream of the bottom protection, and willow branches shall be used to weave a willow fence on the pile, and stone shall be pressed layer by layer.Steam pile driver shall be used to drive rows of piles on the bottom protection, one row for every six piles, with a pile spacing of 2.5m and a row spacing of 4m. The wooden piles shall be connected with iron screws by diagonal battens.A 13m wide wooden bridge is built on the row of piles, and five light railways are paved on it. One small locomotive is used in the middle to pull the iron trolley, and four hand levelled lanes are used on both sides for riprap. ④River diversion.It is planned that the river diversion will be divided into two streams, one is 4.7 km long and the other is 5.4 km long, and the other is 20 m wide at the bottom. The next stream will be one stream, 2.7 km long and 30 m wide at the bottom. The excavation depth will be about 2.6 m, depending on the terrain, with a longitudinal gradient of 1/10000.
Closure progress
(1) Blocking was frustrated: the plugging project started on March 1.After more than two months of cooperation, the progress is relatively smooth. The new west dam embankment and the shallow water fascine have completed 1000m, and the rear berm has been built into a 40m wide dike. The dike groyne has been built near the water. The railway has been paved to the west dam head, the new east dam embankment has been partially completed, the wrapping head is moving forward, the pile driving frame of the deep water bridge has been erected, and the old river approach has been opened one after another.At this time, due to the restoration of the old dike, the funds, materials and relief funds for relocation are not available, so the restoration of the dike cannot be carried out. After negotiation, the parties reached a compromise: the retaining rock dam before the flood season is only 2m high, so that the water flows through the flood area when the water is low, and the flood area and the old road when the water is high.By June 21, the deep-water piling, bridge erection and track laying were completed, with a bridge length of 450m, 119 rows of piles were driven, and other corresponding works were basically completed, starting to riprap at the entrance.But at this time, only 10000 cubic meters of stone were transported, and the riprap dam was far from enough.On June 26, the flood began to rise, and on June 27, four rows of Dongbatou bridge piles were washed away, so the engineering stones had to be thrown down to the retaining piles.By the first ten days of July, all 45 rows of piles in the east had been washed away, and 72 rows of piles in the west were protected by riprap. Riprap will continue later, and half of the phreatic rock dam will be built by the beginning of August.The maximum flood peak flow at Huayuankou in flood season is 8440 m3/s, and the sliding trend is turbulent, and the dam head keeps collapsing, so we have to move all the spare stone willows on the nearby old embankment, and finally pass the flood season.
When the construction resumed on October 5, the old bridge was abandoned first, and a new bridge was planned to be built 350 m downstream of the Koumen. Due to the blocking of flood, bridge piles were moved to the original place on November 5, and the bridge was opened to traffic on December 15, and riprap was started. On December 27, the upstream water surface was raised by 1.2 m, and the river approach began to discharge water, but the diversion only accounted for 1/10 of the whole river, which had little effect.At this time, the flow rate under the bridge increased, and the stone transport could not keep up. On the 20th, four rows of bridge piles fell down, and the suspension bridge was immediately erected at the gate of the bridge cutoff, and the scattered stones and lead wire cages were rushed out. After four days and nights of rescue, the gap was compounded.At this time, the weather was cold and the whole river was flowing.At the beginning of January 1947, the flow rose to 1300 cubic meters per second, the large sliding roof rushed and the drift ice collided, causing bridge piles to topple at many places, and the dam body stung. Eight rows were destroyed in three days. The gap of the stone dam was expanded to 32 m, the water depth was 12 m, the water level difference between upstream and downstream was only 1 m, the stone dam top was completely exposed to the water, and the bridge building and blocking were frustrated again.
(2) Successful mixed plugging: frustrated for three times. The reasons are analyzed as follows: poor quality of the dam itself, small section of the river diversion, few and short water carrying dams.After study, it is decided to use mixed plugging, that is, combining horizontal plugging with vertical plugging.The specific measures are as follows: ① 4 additional river approaches are excavated, and the first two are expected to divide 1/2 of the flow of the whole river. ②The new embankment of Xiba is extended by 250m, and two water carrying dams are built. ③Add layers of willow layer stones at the upstream and top of the rock dam to prevent scouring. ④The bundling box fascine double dam is used to occupy and rush to repair the side dam, the earth cabinet is filled between the main dam and the side dam, and the rear berm is built behind the side dam. ⑤The east and west dam heads are firmly built.On March 7, 1947, the main dam, side dam, Jinmenzhan, flip dam, river diversion and other projects were completed.At this time, the Jinmenkou has shrunk to 25m due to the large number of gabions and willow rollers dropped, and the water depth is 12m. Two suspension bridges are set up on the Jinmenkou, and a floating bridge is set up on the upstream of the Jinmenkou with a large ship ring for the communication and transportation of materials on both sides.At the beginning of the blocking on the 8th, at the same time as the river diversion, large lead wire gabions were used at the upper mouths of the two dams to throw down and fill, and 25m long large willow rolls were thrown at the lower mouths of the two dams.After intense dumping and filling day and night, the dam was finally closed at 4:00 a.m. on the 15th.On the 17th, the edge dam fascine work was closed.On April 20, the gas seepage stopped in the back of the river.On May 4, the celebration meeting was held, and a memorial pavilion was built at the closure site, with a closure monument in the pavilion.
Caulking materials
The closure project was frustrated for many times and the plan was changed, so the labor and materials used exceeded the original budget.According to the statistics, practical labor and materials: willow branches 65 million kg, straw 23.8 million kg, 226000 wooden piles, 269 thousand cubic meters of earthwork, 200000 cubic meters of stone, 112 thousand kg of hemp, 840000 kg of straw rope, 144000 kg of lead wire, 1139 bridge piles, 2350 coils of wire rope, 675 iron anchors. The accumulated labor cost is 3.4 million working days, and the actual work cost is 39 billion yuan (French dollars).The United Nations Relief and Rehabilitation Administration (UNRRA) supplies about 14000 tons of equipment for 59 trains, including 14 tractors, 2 road graders, 2 pile drivers, 6 road rollers, 2 cranes, 4 small locomotives, 29 trucks, 40 jeeps, 2 amphibious boats, 11 generators, 65 carbide lamps, 682000 liters of gasoline, 273000 liters of diesel, etc.[2]
