Construction Technology of the Seventh Generation Winter Warming Greenhouse in Shouguang

Fund Project: Ministry of Finance and Ministry of Agriculture and Rural Affairs: National Modern Agricultural Industry Technology System

Wang Chengzeng

1 The concept of Shouguang winter warm greenhouse and the division of generations

Shouguang winter warm greenhouse refers to the greenhouse that can produce a variety of temperature-loving vegetables without artificial heating in the deep winter of Shouguang. The structural standards of the fifth-generation winter-warm greenhouse in Shouguang are: large back wall, digging type, and a width of 10-13 m inside the shed. The structural standard of the sixth-generation winter-warm greenhouse in Shouguang is: large rear wall, digging type, and the width of the shed is 13-18 m. The structural standard of the seventh-generation winter warm greenhouse in Shouguang is: large back wall, digging type, and the width of the greenhouse is 18~29 m.

2 Technical breakthrough points

In 2015, with the introduction of the two reform policies of Shouguang greenhouses and the increasing demand for expanding the planting area of single greenhouses, experiments were started to further widen and lengthen the greenhouses to solve the problem that the width did not exceed 18 m in the past.

First, the test adopts lightweight waterproof thermal insulation quilt, which solves the problem of long and heavy thermal insulation quilt. The second is to increase the height of the rear shed, which solves the problem of poor ventilation in spring and difficulty in cooling the shed. The third is to widen and increase the height of the entrance door. The original door is 1.2 m wide and 2 m high. Now the door is 1.7-1.8 m wide and 2.2-2.5 m high. The problem of inconvenient entry and exit of various machinery such as machine and rotary tiller has improved the mechanization of vegetable cultivation in the greenhouse.

With the solution of key technologies, a small-scale promotion was carried out in 2017. First, 20 sheds with a length of 260-320 m and an inner diameter of 20 m were built in Shouguang Dongpianguan Village; construction in 2018 4 sheds with a length of 350 m and an inner diameter of 21.5 m wide; 20 sheds with a length of 280-320 m and an inner diameter of 23 m wide in 2019; 40 sheds with a length of 150-370 m and an inner diameter of 25 m in 2020 m; 42 sheds will be built in 2021, with a length of 160-320 m and an inner diameter of 26 m wide. The length of the greenhouse is determined according to the length of the plot, but the width is an important indicator, and the next step is to plan to impact the width of 29 m.

3 Construction technology (taking the inner width of the shed 26 m as an example)

3.1 Structure and data

The highest point in the shed is 9.3 m, the inner diameter is 26 m wide, the length is more than 150 m, and the longest is 400 m. The bottom width of the rear wall is 13 m, the top width is 2.2-2.5 m, and the height is 8.3 m. The walkway in the shed is 1.5-1.8 m, the entrance and exit holes are 1.7-1.8 m wide and 2.2-2.5 m high.

3.2 Plot planning

Choose a plot with flat terrain, convenient transportation, no surrounding by tall buildings, deep groundwater level, non-sanded soil, convenient drainage, and no pollution sources around. The greenhouses are located from north to south, each shed is planned to be 48-50 m wide from north to south and 150-400 m long from east to west.

The specific arrangement of north and south, from north to south, 1 m of open space, 13 m of wall (the bottom of the wall), 26 m of inner width of the shed, 2 m of walkway in front of the shed, 4-6 m of seepage ditch in front of the shed, 2 m and front row Shed slope, a total of 48 ~ 50 m.

3.3 Construction Requirements for Greenhouse Earth Walls

13m from north to south, the edge of the bottom corner of the wall is drawn, 6m from the south to open a 2m deep groove, 40cm of soil is pressed 1 layer, a total of 5 layers of flat ground. Above the ground, the bottom 50 cm is pressed 1 layer, and 10 layers are pressed; the upper 60 cm is pressed 1 layer, and 3 layers are pressed. The bottom is thin and the upper is thick, a total of 13 layers are pressed, and the height above the ground is about 6.8 m.

The top of the shed wall is tightly pressed with a chain rail car. After the wall is built, the upper width is 2.2-2.5 m, the base is about 13 m, and the inner slope of the shed wall is about 100:40.

Note that the horizontal excavation method is adopted to borrow soil for building walls, which can prevent local settlement in the future. Dig about 1.8 m underground. The soil moisture should be suitable, not too wet or too dry. The wall must be built with a professional team, strictly in accordance with the construction requirements, and the phenomenon of wall collapse must not occur.

3.4 Greenhouse uprights and post-laying requirements

Cement columns need to go to the prefabrication yard to book in advance. There are 2 rows of columns behind the aisle, and one row is the column built at the top. mm of cold-drawn steel bars, the upper side is built on the back, the row with steel beams is built with 30-35 cm in the south, and the row of non-compressed steel beams is built with 35-40 cm in the south. The column is buried 0.5 m below the ground, and there is one for every 2 m in the east and west.

The other row is the column of the top steel beam, the specification (thickness, width) is 9 cm × 13 cm, and the length is 9.2 m. There are 8 cold-drawn steel bars with a thickness of not less than 5 mm. This column is vertical or slightly inclined to the north. The steel beam is placed on the beam to prevent bending of the steel beam when the quilt reaches the top. The buried depth is 0.2 m, and there is one every 4 m from east to west.

It is best to use a nest of two columns for the 2 rows of uprights behind the aisle.

The first row of columns in front of the aisle, the specifications (thickness and width) are 9 cm × 13 cm, and the length is 9.5 m. There are 8 cold-drawn steel bars with a thickness of not less than 5 mm. According to the width of the walkway) buried depth of 1.2 m, 1 root every 4 m.

The second row of columns in front of the aisle, specifications (thickness, width) 9 cm × 13 cm, 9 m long, with 8 cold-drawn steel bars with a thickness of not less than 5 mm, buried at a depth of 3 m from the first row of columns 1.1 m, something every 4 m 1.

The third row of uprights in front of the aisle, the specifications (thickness and width) are 9 cm×13 cm, 8.5 m long, and there are 8 cold-drawn steel bars with a thickness of not less than 5 mm. It is buried at a depth of 3 m from the second row of uprights. 1 m, something every 4 m 1.

The 4th row of columns in front of the aisle, the specifications (thickness, width) are 8 cm×12 cm, 7.8 m long, and there are 8 cold-drawn steel bars with a thickness of not less than 4.5 mm, buried at a depth of 3 m from the 3rd row of columns 1 m, something every 4 m 1.

The fifth row of columns in front of the aisle, the specifications (thickness, width) are 8 cm × 12 cm, 7 m long, and there are 7 cold-drawn steel bars with a thickness of not less than 4.2 mm, buried at a depth of 3 m from the fifth row of columns 0.9 m, 1 piece every 4 m.

The 6th row of columns in front of the aisle, specifications (thickness, width) 8 cm × 12 cm, 6 m long, with 6 cold-drawn steel bars with a thickness of not less than 4 mm, buried at a depth of 3 m from the 6th row of columns 0.8 m, 1 piece every 4 m.

The 7th row of uprights in front of the aisle, specifications (thickness, width) 8 cm × 12 cm, 5 m long, with 6 cold-drawn steel bars with a thickness of not less than 4 mm, buried at a depth of 3.1 m from the 7th row of uprights 0.7 m, 1 piece every 4 m.

The 8th row of columns in front of the aisle, the specifications (thickness, width) are 8 cm×12 cm, 3.6 m long, and there are 6 cold-drawn steel bars with a thickness of not less than 4 mm. It is buried at a depth of 3.1 m from the 8th row of columns. 0.6 m, something every 4 m 1.

The 9th row of columns in front of the aisle (also the southernmost column), specifications (thickness, width) 8 cm × 12 cm, length 2.3 m, there are 8 cold-drawn steel bars with a thickness of not less than 4.5 mm, in the distance from the 9th row The column is 3.1 m, buried at a depth of 0.6 m, and there is one for every 2 m from east to west. The upper end of this row of columns generally slopes 0.3 m to the south to prevent rainwater from damaging the slope.

Note that 1-2 hard red bricks should be placed at the bottom of each column.

Back-lay, specifications (thickness, width) 9 cm×20 cm, length 2.5 m, there are 10 bars (note: 4 on the top, 6 on the bottom, do not reverse) cold-drawn steel bars with a thickness of not less than 5 mm, and the back-laying installation is inclined degrees around 45°.

Note: The shed is 1 room every 4 m, and you can also set the width of each room according to your own planting habits, preferably 4 m is 1 room, and plant 6 rows, which is convenient for mechanical furrowing.

Due to the oblique angle between the east and west mountains, the tops of the columns on both sides of the bottom are 4 to 5 m away from the tops of the two gables. If the distance is large, a beam should be added at the top, and a top column should be added in the middle. In the middle of the beam, the beam and the top column are preferably welded with steel pipes with a diameter of 73 mm and a thickness of 3.5 mm, which can prevent the back slope from sinking.

3.5 Installation of steel wire

Use high-quality hot-dip galvanized steel wire of No. 28. The interval between the steel wires behind the shed is 8 cm, the interval between the steel wires at the tuyere is 12 cm, and the interval between the steel wires on the shed surface is 25 cm.

Before going up the back slope soil, the rear columns are reinforced with 3 steel wires, and the front 2 rows are reinforced with 2 to 3 steel wires. The method is to pull 3 steel wires from east to west for each row of columns, with a distance of 1.5 to 2.0 m up and down, and use iron wires for each column. Lock to prevent shifting.

East and west hanging vegetable steel wire is pulled 1 in each row, the two mountains are drilled with rhinestones, and the outside is fixed on the ground anchor. It is best to use 2 to 3 wire for hanging vegetables in the front and rear 2 rows of columns. In advance, at the bottom of each steel beam, 20 cm away from the front end, weld a galvanized screw cap for stringing the wire for hanging vegetables.

It is best to use double steel wire for the pulley wire of the air outlet, which is fixed on the steel beam in advance.

It is best to use double steel wires to fix the large membrane, and each steel pipe is bundled.

3 to 4 wires are used to tie the lamination rope at the back. This steel wire is also used to fix thermal insulation quilts and floating membranes (rainproof membranes).

The top end of the steel beam is made of double steel wire, used for fixing the film supporting steel pipe, and can also be replaced by a 4 cm × 4 cm hot-dip galvanized triangle iron.

The distance between the retaining wires on the front face is 10 cm, and the vertical oil poles are welded at both ends to pull the wires, which is convenient for reserving the exits for entering and exiting large machinery.

3.6 Hot-dip galvanized steel pipe

The steel beam steel pipe is generally 1.5 inches (1 inch = 3.33 cm, the same below), the thickness is 2.75 ~ 3.00 mm, and the shrinkage is welded. Lay the steel pipe with 1 inch, the thickness is 1.0 ~ 1.2 mm, and the steel pipe is connected by shrinking. 1 piece about 70 cm.

Add a 6m long water-flowing steel pipe between the steel pipes at the tuyere to prevent the top of the tuyere from taking water.

The east and west steel pipes of the front face are made of 1.5-inch hot-dip galvanized steel pipes with a thickness of 2.5 mm, and the steel pipes are welded with screws about 70 cm apart to prepare for inserting film steel pipes.

When bundling film steel pipes, one steel pipe can be bundled 4 times. A bundle should be added to the film support rod at the steel wire position above the large film.

The blower steel pipe is 1 inch and 2 mm thick. It is best to ask the installation team to install and debug it.

3.7 Ground Anchor

The anchors of the two mountains are 1.8-2.0 m in length, with extra dense in the north, dense in the middle, and slightly thin in the front.

The ground anchors tied to the lamination ropes in the front should be 70 cm long (if the front face is dug out and placed at a distance of 0.8 m from the front column, the height is the same), and the distance is about 70 cm.

1.2-1.5 m ground anchors are used behind the shed, with a spacing of 1.5-2.0 m.

3.8 Selection of quilt, oil rod and roller blind machine

The top and bottom of the thermal insulation quilt are mostly made of PE cloth, and the middle is made of 1 200 g/m 2 space cotton and 0.5 cm thick foam. Velcro closure on both sides. Add a layer of 6 m long non-woven fabric on the bottom surface of the upper head to prevent aging and damage caused by sun exposure after rolling up.Use a 9m-long 90mm oil rod on each side of the roller blind machine, and use 73mm oil rods for the other ones. It is better to use the one with a casing inside, which is not easy to rust. It is better to thicken the head. After tightening, welding, except for both sides of the machine head, generally do not use flanges for butt joints.

According to the length and width of the greenhouse, the roller blind machine decides whether to use a large five-axis or a six-axis, and the motor is equipped with a 1.5-2.2 kW asynchronous three-phase motor.

Roller shutter machine bridge, welded with galvanized steel pipe, with 75 pipes (2.5 inches) on the top, 60 pipes (2 inches) on the bottom 2, and hot-dip galvanized steel bars of 16-18 mm for the middle connecting bars; triangular welding of steel bars, etc. The waist is the best, that is, the included angle is 45°.

3.9 Selection of shed film, vent film and slope protection material

It is best to use high-quality PO film as the shed film. The PO film has strong wind resistance and can be used continuously for 2 to 3 years.

It is best to use 15 silk (0.15 mm) PO film for the vent film, which can be used for 5 to 7 years.

It is best to wear a steel wire to hang it in the middle of the slope protection non-woven fabric to prevent it from sagging when it rains, which can increase the service life. Or use PE cloth, which is light and has a good effect after trial. Use a piece of non-woven fabric or all PE cloth on the top, and cover it with an old quilt or non-woven fabric.

It is best to add a layer of film to the front face felt of the shed to prevent the rain from seeping into the shed and washing out the front face.

3.10 Special Notes

① The ground anchor on the front face of the shed can be buried in alignment with the steel pipe, and the distance from the front column should not be too close to prevent the film from being unable to be laminated in the future, which will cause the soil behind the shed to be easily washed into the shed. It is most suitable for the ground anchor to be placed 70-80 cm away from the pillar on the front face of the shed.

② The ground anchor of the rear slope protection should be buckled in and as deep as possible to prevent the front face of the rear adjacent port from being dug out.

③ Use double steel wire or thickened steel wire to hang and release the pulley of the fan, and fix it well to prevent it from being pulled away.