Some Improvements and Inadequacies in the Construction of Vegetable Greenhouses in Recent Years
At present, the planning and design of vegetable greenhouses is more and more reasonable, construction and construction levels are getting higher and higher, and new materials and new processes are becoming more and more common. As a result, the performance of vegetable greenhouses such as pressure resistance, heat preservation, wind resistance, and anti-mite performance is greatly improved. Increased in magnitude. However, there are still many deficiencies in the construction of vegetable greenhouses in some regions, resulting in reduced service life and even affecting the normal production of vegetables. Below, we come to tease out the current improvements and shortages in the construction of vegetable greenhouses for the reference of farmers.
First, improvement measures
1. A new method for installing a support frame and installing a pre-embedded iron to install a steel frame
In the past, shed face skeletons were mostly welded using 2-3 galvanized steel pipes with a length of 6 meters. Before installation, a W-shaped connection piece is welded on the upper end of the steel pipe. When the installation is completed, the connection piece of the steel pipe is directly clamped onto the post-laying column, and finally the wire is used for binding and fixing. Last year, the reporter interviewed learned that a more scientific and reasonable method of installing the shed face skeleton:
On the support frame: 1. A single steel pipe to be converted into a steel frame with a pull steel reinforcement. That is, a row of thin steel bars is welded underneath each steel pipe, and between steel bars and steel pipes, they are connected by wavy short and fine steel bars. It is understood that the steel frame has stronger support to the shed, and it is not easily deformed. Even during the process of rolling the rake, the up and down range of the steel frame is very small. 2. A section of support frame is added to the upper end of the steel frame, and the support frame is also connected using a pull-out rebar. In this way, the steel frame can be separately placed on the back wall, and the steel frame of the shed face does not need to be slotted on the post pillar.
Under the pre-embedded iron: 1. Corresponding to the digging of each pipe under the cement, triangle iron on the cement. But do not directly connect the steel pipe to the cement in front of the shed, so that the connection is easy to loosen. It is better to loosen the cement in the planing hole in the previous week, fix the triangle iron on the upper end of the cement, and then weld the steel pipe and triangle iron. Guaranteed firmness. 2. The bamboo pole and the steel pipe pull a wire at the bottom. After the steel pipe is connected, the bamboo poles on the shed can be directly connected to the ground and inserted into the ground about 10 centimeters. In order to ensure the stability, a steel wire can be pulled at the lower end of the steel pipe and the bamboo pole, and binding is performed at the interface, and the effect is good.
Reporter analysis: steel pipe welded into a steel frame, steel frame with support frame, support frame at the bottom with a iron plate base, can be directly embedded in the back wall, which is more than a single steel pipe slot in the post on the pillars of a more solid. Greenhouses are made of steel frame to make the shelf structure, which improves the firmness of the steel frame and improves the pressure resistance of the greenhouse. For this, the vast number of shanty households can learn from it.
In addition, the main steel beam of the greenhouse is directly welded on the floor in front of the shed. Not only the front face of the greenhouse is stabilized, but also the shape of the greenhouse shed is more reasonable and the dripability is better.
2.Using the ultra-flat hose to measure the buried column to ensure that things are arranged in rows and north and south in rows. The distribution is even and consistent from top to bottom.
In order to enhance the firmness of the sheds, improve the bearing capacity of the columns, and facilitate the management and operation, the columns must be laid in such a way that things are arranged in rows and north and south in rows. The distribution is uniform and consistent from top to bottom. Here, the reporter recommended using ultra-flat hoses for measurement. The measuring tool uses the principle of a communicator to find the horizontal line between two columns. The specific method is as follows:
The first step: determine the position of the marking. Measured from the lower end of the column with a metre ruler, the prescribed height is 1.5 meters and clearly marked with a stylus.
The second step: First bury the first row of posts and fix them. Make sure that the depth of burial is 55 centimeters. Do not forget the tiles at the bottom of the columns.
The third step is to dig the last column of pits well, and dig deep enough, about 60 centimeters (deep enough to backfill the soil), and put the column into the pit. One person holds an ultra-flat hose (must be filled with water in advance and tied up at both ends), lean it against the marking line of the first row of columns, and the other person holds the other end of the ultra-flat hose and also leans on the last one. Rows of column markings. If the horizontal plane of the ultra-flat hose at this site is beyond the reticle, it indicates that the pillar is buried deep and the backfill pad is required to be filled. On the contrary, the level of the ultra-flat hose is lower than the standard line, indicating that the column is buried and it is necessary to dig again. Through continuous leveling, the horizontal line between the two columns can be finalized. Similarly, if all the pillars are kept at the same level using this method, then the greenhouses can be constructed with the same level of floor coverage.
3. Three kinds of available shed support
Last year, reporters interviewed the countryside to learn about the support of three kinds of materials, which are summarised and introduced as follows.
The first, 8# steel. The main reason is that the rebar's toughness is much stronger than that of the bamboo pole, which can maximize the safety factor of the front face of the greenhouse. In recent years, with the heightening, widening and lengthening of greenhouses, the weight of greenhouse insulation equipment has become heavier and heavier. Combined with the application of roller shutters, bamboo rafts have been used in the past to meet their bearing capacity. When the shutter was first rolled up, it was very easy to break the bamboo raft and put forward higher requirements for the front face of the greenhouse. However, the steel bars did not have such problems.
Second: PVC greenhouse tube. Practice has proved that the PVC greenhouse pipe is used for the construction of the front face of the greenhouse with good effect, aging resistance, easy installation, medium cost (2.2 yuan/m), and a smooth surface without damaging the shed film (except for the PVC film, since the two are in contact, Reactive under high temperature and strong light, PVC film becomes black and aging).
The third kind: galvanized steel pipe. In order to meet the needs of the erect structure of the front face of the greenhouse, some farmers processed the skeleton steel pipes of the greenhouse to form a “┑†shape, which is both the skeleton of the greenhouse and the front face of the greenhouse. According to the farmers, the law can greatly improve the support ability of the shed's front face, and the use effect is good.
Second, the lack of construction
1. The east and west walls are not "open" and the "small room" is not set properly
Last year, the reporter discovered during telephone conversations with farmers in Henan's Quzhou and Shanxi's Quzhou. They overlooked the planning and construction of "little rooms" in greenhouses. The width of the standard rooms is close to 4 meters. The actual construction of the standard room is the most suitable for 3.5 meters/room, which is conducive to the rational arrangement of vegetable cultivation and does not affect the firmness of the shed.
There are no "small rooms" on both sides of the greenhouse, indicating that the east and west walls do not "open" to the outside. The original "little room" was attributed to a large standard plan. As a result, the width of the small room would be too large. The pressure on the skeleton of the greenhouse is increased, and it is easy to collapse when there is heavy snow.
The reporter believes that with the continuous upgrade and reconstruction of greenhouses, more and more high-rise, widening and lengthening booths have been added. Together with the application of greenhouse shutters and thickening and lengthening grasshoppers, the overall carrying capacity of the greenhouse has been proposed. higher requirement. In order to plan the construction of the shed more rationally, the reporter suggested setting up a “small room†in the middle of the shed. Its width is 2.5-3 meters. Through the setting of a small room, the carrying capacity of the booth can be significantly increased, and the shutter can be safely operated to deal with hazards such as storms and snow.
So, what kind of "little room" planning design in the shed is more reasonable? The reporter recommended two methods:
One is to arrange "small rooms" on both sides of the greenhouse. Its construction techniques are: the first step, the erection of pillars. In a 12-meter-span room, a standard one will be lined with 4-5 columns from north to south, while a small room will only need to be embedded with three: the post-pillar column 5.5 meters, the middle support column 3.6 meters, and the shed front face column. 1.5 m. The rear pillars are aligned with the front face columns of the shed. The middle support pillars should be half a meter away from the wall. In the second step, pull the diagonal bar. First measure the shed front face column to the middle support column and then to the east (west) wall of the shed, and then select the appropriate bamboo rod as the crossbar. Finally, the bamboo poles are placed diagonally on the pillars and walls, and the bamboo poles and the pillars are fastened with iron wire. The third step is to pull the steel wire and put bamboo on it. After the sloping bar is fixed, the steel wire can be stretched east to west. Wherever the diagonal bar and the steel wire intersect, they are all tied with wire. Finally, install the bamboo film on the shed wire.
The other is to build "little rooms" in the middle of the greenhouse. This kind of construction method is simple and is the same as the ordinary burial column building shed. Practice has proved that this kind of construction method has strengthened the load capacity in the middle of the greenhouse and provided convenience for the installation and operation of the rolling machine.
2. The lamination method needs to be improved
When interviewed by reporters in the Zibo Gaoqing area, it was found that there are two kinds of laminating methods commonly used by vegetable growers in the region: one is covered by a shed film, and anchors are laid under the roots of the east and west walls, corresponding to pull steel wire lamination, generally 9 meters. More than 6-8 pieces of laminar steel wire are arranged in a wide booth. The other type is covered with a shed film, respectively, in the roof, one meter away from the south end of the shed at the east-west pull a wire, and then the north-south to the upper and lower ends of the nylon rope tanning film. I think that the farmers are not good enough.
Analysis believes that the east-west steel wire film, although the steel wire is stronger than the nylon rope, but after all, due to factors such as bamboo film on the shelter, it is easy to be uneven, which causes the film steel wire can not fully suppress the film, encountered When there is a windy weather, the shed film stirs up and down, and it is easy to destroy the shed film.
In addition, the second method of lamination for high-vegetable vegetable farmers is not to embed anchors at the south end of the shed, but instead of replacing it with a steel wire, we found that, in the penthouses using this method, the steel wire and the nylon ropes were often exposed. Worn out bad situation. Here, to remind the vegetable grower to improve, you can pull a steel wire in the east-west direction of the roof, and lay a anchor at a distance of 1.3 meters at the south end of the shed. After the cover film is covered, the nylon rope is used to press the film, and the upper end is fastened to the steel wire. At the bottom, the anchor is on the ground.
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