First, due to the diversification of investment subjects in greening construction, it is difficult for government departments to grasp, so that some greening projects, such as the greening of residential quarters, must be greened in order to meet the requirements of the planning department for 30% green space rate on the one hand, and to cater to people's current fashion requirements of "green life" and raise housing prices on the other hand. At the same time, from the perspective of saving money and reducing costs, it is also considered that some self-employed people are invited to plant trees and spread grass at will. The whole project has not been designed by a formal design unit, and the landscape effect is poor and the grade is low.
Second, the greening construction team is mixed, and it is difficult to fully reflect the design ideas of the project. Greening engineering is different from building engineering, and its rigor and technology are not very strong, which makes many people mistakenly think that greening construction is all kinds of trees and grass, and no one can do it. Coupled with its considerable profits, many low-quality individual teams have flocked to the greening construction industry and institutions to copy drawings. As everyone knows, "three points for design and seven points for construction", a good landscape project needs designers and constructors to complete together.
Third, there is no special greening supervision company, and the greening construction supervision is mostly held by the construction supervision. In addition, in the Code for Construction and Acceptance of Urban Greening Projects, there are few mandatory clauses with "must", which often appear: if the soil is good, just plant it; Tree pits should not be big, just plant them; You can do without applying base fertilizer. Only pay attention to the final landscape effect, not to soil, base fertilizer, pit specifications and so on. , making some trees grow poorly and increasing the difficulty of later maintenance and management.
The grade and quality of greening projects are directly related to the landscape effect, city image and cultural taste of a city. Therefore, it is imperative to strengthen the management of greening construction and standardize the greening market.
1, implement the approval procedures for greening project construction.
We can learn from the practice of the construction industry. Any unit carrying out greening projects needs to report to the competent department of greening and apply for a construction permit. The competent department of greening mainly reviews the design scheme of its greening project (the design drawings must come from the design unit with the qualification of greening design), and comprehensively reviews the landscape, ecology and function of its green space and its coordination with the surrounding environment. Only after the approval of the competent department of greening can the construction be carried out according to this. This will not only help to improve the level and grade of greening projects, but also facilitate the greening authorities to grasp the greening situation of the whole society, so as to formulate macro-planning and carry out macro-control of cities.
2, the implementation of green building market access system.
In order to achieve a certain scale of greening projects, it is necessary to implement the bidding system, let the construction units with certain greening construction qualifications and achievements participate, implement the system of survival of the fittest, and let those with poor construction quality and poor reputation quit the greening construction industry. Even if it is a small-scale greening project construction, it must be qualified for greening construction, and those who are not qualified are not allowed to engage in any greening project construction activities.
3, greening construction supervision system.
Establish a greening construction supervision company composed of not only architects, hydropower engineers, but also landscape engineers to control the investment, progress and quality of greening projects.
(1) Organize the design disclosure and the blue prints.the design.
Greening construction is different from building engineering, as long as it is carried out in strict accordance with the drawings. The greening construction process is also a creative process, and there is a problem of how to fully embody the design ideas and concepts. Therefore, the disclosure of drawings is extremely important, which requires the design unit to introduce the design intention in detail, and the construction unit to deeply understand the overall design idea of the project so as to use it flexibly in construction. For example, when planting trees, which one is straight and which one is inclined, the angle of inclination, how to make it match the harmonious and lively expectation, vivid and interesting, these are not reflected on the construction drawing paper.
(2) Strengthen the quality management of the construction process.
Pay attention to soil treatment.
The quality of soil is directly related to the future growth of plants. It is necessary to analyze its physical and chemical properties, such as pH value, porosity, water permeability, water holding capacity, etc., and then take corresponding measures, such as disinfection, application of base fertilizer, exotic soil, etc. In particular, the excavation depth of soil, the quality of foreign soil, the maturity and application amount of base fertilizer and the flatness of terrain should meet the relevant requirements.
Treatment of fixed-point pay-off
Generally, it is required that the location is accurate and clearly marked. The planting hole is marked with the center point, and the planting groove is marked with the sideline. But under special circumstances, it needs to be handled flexibly. For example, when planting trees in the isolation belt, it is required to keep a distance of 2 meters from the lamppost when meeting it, so the setting-out must be handled flexibly and the spacing between trees should be adjusted appropriately. There is also the fixed point of street trees. Due to underground pipelines, fire hydrants, shops and other factors on both sides of the road, some appropriate adjustments are often needed.
Digging planting pits and planting troughs
The excavation of planting holes and planting grooves depends on the root system of seedlings, the diameter of soil balls and soil conditions, especially the planting holes with poor soil quality must be dug deep, and then base fertilizer and exotic soil should be applied to create a small environment conducive to plant growth.
Ensure the quality of seedlings
Strictly control the variety, plant type, crown width, height, trunk diameter, soil ball size and root development of seedlings, and select excellent seedlings that meet the design requirements, grow healthily, have no mechanical damage and no pests and diseases.
Seedling planting
Before planting seedlings, the roots and crowns of seedlings should be trimmed to remove the non-perishable packaging materials with soil balls; When planting trees with soil balls, the bottom of the planting hole should be leveled, and the bottom of the planting hole should be filled with soil into a cone for bare roots; When filling the soil, it should be compacted in layers, preferably with a hoe, leaving no gap; Pay attention to the direction of the surface.
Root water must be poured thoroughly within 24 hours after planting.
Fixed stay
Trees over 5 cm should be fixed with posts, and the fixtures should be kept neat.
Only in strict accordance with the construction technology, after the completion of each working procedure, can it be handed over to the next working procedure to continue the construction. Only by handing over the inspection step by step can the construction quality be guaranteed.
4. Acceptance of greening projects in advance in construction projects In order to ensure the greening in place and the greening quality as part of the ancillary works of the building, the greening project must first pass the acceptance of the main building project. By the competent department of greening, the construction unit and supervision * * * to participate in the acceptance. In order to prevent buildings from being unused for many years, the green land reserved is overgrown with weeds and desolate. It is believed that as long as we strengthen the regulation and control of greening project construction from the macro perspective and strengthen the construction management from the micro perspective, we will certainly be able to ensure the construction quality of greening projects and create a high-quality and high-grade quality project that conforms to ecology, pays attention to landscape and shows concern for people at the same time.
How to construct the landscaping project?
Big trees in big tree transplantation refer to trees, sub-trees and trees with DBH of 10 cm. The sources of transplanted trees can be divided into two types: artificial cultivation of transplanted trees and natural growth of transplanted trees. Artificial transplanted trees are trees cultivated through various technical measures, and the transplanted trees can adapt to various ecological environments.
Get ready.
(1) Master the biological characteristics, ecological habits and environmental factors such as the source of seedlings and the soil in the planting area. From the analysis of plant physiology, the growth of every tree, whether artificial or natural, is directional. Under the same site conditions, the crown width of sunny slope is larger than that of shady slope. The lateral root of sunny slope is shorter than that of shady slope; The leaves on sunny slopes are ten shady slopes; Sunny slopes bear more fruits than shady slopes. Therefore, lead oil must be used before transplantation, and a mark must be drawn at the breast height position facing the azimuth.
(2) Prepare necessary mechanical facilities (such as cranes, flatbed cars, etc.). ), manpower and auxiliary materials, on-the-spot investigation of the walking route, formulate detailed transportation and planting scheme.
③ 1 seedling treatment: select seedlings that are robust, fully developed, free from pests and diseases and meet the requirements of greening design, and carry out thinning, short cutting and trunk wound treatment (white ready mixed paint or lime milk) in advance.
④ Treatment of tree holes in the planting area: For example, besides considering the size of clods, the working space in artificial pits should be reserved (40-50 cm should be reserved for the whole pit edge of clods), and the base of tree holes: soil keeps moisture. If it needs to be replaced, the virtual soil must be tamped and sunk with water (to prevent the trees from tilting after being put in because of uneven soil quality).
It is the best time to plant trees after defoliation. At this time, the trees are still dormant and the sap has not yet flowed out. In the urban reconstruction and expansion project, big trees can be transplanted in the peak season (summer), preferably in cloudy days or before and after rainfall. It is necessary to follow the trend, transport, plant and water.
Seedling raising: for large-area tree species transplanted out of season, clods must be brought when transplanting. The diameter of the clod is about 65438+ 0/3 of the height of the tree, and the clod should be complete and semi-complete. The mound is shaped like an apple, and the bottom does not exceed 1/3 of the diameter of the mound. Tie it tightly with sacks or hemp rope. When the seedlings are hoisted by crane, a board with a thickness of 1 inch should be placed on the contact surface between the wire rope and the clod to prevent the clod from loosening due to excessive local stress.
Pruning: Pruning is mainly to reduce the evaporation of water from trees and facilitate transportation and planting. If there are side branches that affect transportation, they can be shortened appropriately. In principle, conifers should not be pruned, and broadleaf trees can be pruned appropriately.
Transportation: The seedlings are too high and must be placed on the walking line at a certain inclination angle. In order to prevent the lower branches from being broken, they should be supported on transport vehicles.
Planting: when planting, the trees should be kept upright and in the right direction (for example, the seedling period of trees with misplaced directions is extended by about 7 days, and the survival rate is 20% lower). According to the requirements of seedling depth, seedlings should be placed in into the pit. The planting depth is slightly 2-3 cm deeper than the original. Cut the straw rope (if it is hemp rope, be sure to take it out), take out the cattail bag or sack piece, and tamp it while burying the soil. When planting bare-rooted trees, the roots should be stretched and not nested. When the soil is filled to 1/2 of the pit, the seedlings should be gently lifted several times, and the transplanted trees should be supported in layers to prevent the roots from shaking and breathing. Do a good job of triangular support or lead wire hanging piles. The part where the pillar meets the trunk should be padded with a piece of cattail to prevent the bark from being worn out. And timely irrigation, 1 irrigation must be fully infiltrated. In order to reduce the water evaporation of newly planted trees, except for a few trees that can be re-cut, trees that should be lightly cut or thinned should be sprayed with water frequently to increase the air humidity of the local environment; Measures such as temporary shading can also be taken. In addition, the application of auxin such as naphthylacetic acid can promote the injured roots to grow new roots quickly; Spraying transpiration inhibitor on the trunk can reduce the evaporation of the tree and improve the survival rate of transplantation.
maintenance management
(1) Water conservation: The newly transplanted trees have reduced water absorption capacity due to root damage, so ensuring sufficient water is the key to ensure the survival of trees. In addition to watering in time, it is also necessary to spray water and fog to moisturize or change medicine on the trunk according to the tree species and weather conditions.
② Pest control: Newly planted trees have poor resistance to pests and diseases, so it is necessary to observe the occurrence of local pests and diseases at any time and take timely control measures.
③ Drainage: After transplanting big trees, the requirements for water are different according to different tree species. For example, ash likes wet soil, cedar avoids low-lying and wet waterlogging, and the groundwater level is high. Therefore, after transplanting ash, water it properly, and cedar should pay attention to timely drainage in rainy season.
④ Burn prevention in summer and cold prevention in winter: high temperature in summer and strong light in the north. Precious tree species should be sprayed with water mist to cool down after transplantation, and umbrellas should be made if necessary. In winter, the temperature is the best time for trees to lose their leaves. At this time, the trees are still in a dormant state and the sap has not yet flowed out. In the urban reconstruction and expansion project, big trees can be transplanted in the peak season (summer), preferably in cloudy days or before and after rainfall. It is necessary to follow the trend, transport, plant and water.
It is worth noting that although transplanting big trees is helpful to improve the urban ecological environment, we should also consider its technical difficulty and economic input, adjust measures to local conditions, and we should not blindly follow suit, let alone destroy natural resources at will.
(2) Technical points of planting other trees, shrubs and lawns.
1 Clean up the site
Clean up all rubbish, weeds and sundries on the construction site.
2 site leveling
In strict accordance with the design standards and landscape requirements, earthwork backfilling and leveling shall be carried out to the design elevation, and site excavation shall be carried out. The thickness of soil layer planted with turf is not less than 30cm, the flower bed is not less than 40cm, and the trees are not less than 70cm. Arrange the broken topsoil into a plane or curved surface that meets the requirements, and adjust the overall slope according to the design requirements of the drawings. Elevation meets the requirements. In case of special circumstances, it shall be handled through consultation with the owner.
Configuration of construction tools: bulldozers, transport vehicles, cranes, backhoes, shovels, shovels, hoes and trolleys.
Construction content: The construction party is responsible for leveling the site. Use the above machinery and tools to level the slopes that do not meet the design requirements, level the high slopes and fill the low ponds. Special sites, such as lawns, should have a suitable drainage slope, generally 2.5%-3%, and the edge should be 3-5 cm lower than the curb.
Dig and loosen the site with a thickness of not less than 50 cm. When conditions do not permit, ensure that the soil thickness for lawn planting is not less than 30cm, and the soil thickness for flower bed planting is not less than 40cm, and roll the clods. For low flower beds, it should be 5- 10 cm above the ground to meet the requirements of seedling planting.
Inspection items: flatness, weed removal degree and scarification quality.
3 Pay-off fixed point
According to the proportion of design drawings, the position and layout of various trees in the design drawings are reflected to the actual site to ensure that the layout of seedlings meets the actual requirements. When the actual situation conflicts with the drawings, appropriate adjustments shall be made with the consent of the supervisor.
Building tools: hoe, shovel, tape measure, stake, wire, lime.
Work content: according to the drawings, use the above tools to set out trees, shrubs, ground cover, turf, sketches, etc. On the fixed point of plastic engineering site by grid method.
For regular shrub flower beds, the setting-out should be accurate, the planting should be pressed, and the pattern should be clear. Hedges should be dug up. The size of the planting trough depends on the design requirements and soil ball specifications.
Inspection items: the fixed-point setting-out size of the construction drawing should be accurate. Conduct inspection according to the company's quality inspection standards and make a written record.
○4 Dig planting holes and apply base fertilizer.
The planting holes of trees are mainly round, and the flowers and shrubs adopt row holes, which are about 30cm larger than the diameter of root balls. The base fertilizer should be applied according to the work instruction.
Methods and technical points of digging planting holes;
Tools: hoe, shovel, spade.
Work content: Determine the specifications of planting holes according to the marking line of fixed-point lofting and the size of soil balls of trees. Generally, the diameter of tree holes is 20-30cm larger than the specified diameter of soil balls. According to the design requirements, determine the lofting range or shape of flower beds and hedgerow planting holes. Hedges are mainly strip-shaped, and flower beds are mainly geometric. A ditch with a width of 3-5 cm and a depth of 3-5 cm should be left around the flower beds and hedges, and the depth of digging soil should be15-3-5 cm.
Inspection contents: specifications and quality of seedlings, quality of planting holes, cleanliness of sundries and stones. Check and accept according to the company's relevant quality standards, and record.
Matters needing attention: pay attention to the combination of design and construction drawing with the specific situation on site, and put forward reasonable suggestions for the places that cannot be constructed according to the design requirements.
Methods and technical points of applying base fertilizer;
Building tools: hoes and shovels.
Work content: basic fertilizer types: organic fertilizer, compound fertilizer and organic compound fertilizer.
The amount of base fertilizer for lawns and flower beds should be controlled at around 10g/m2.
Fertilization method: mix with soil and backfill the bottom of the tree hole; The lawn and flower bed are spread out and turned 30㎝ to fully mix the soil and fertilizer.
Check items: whether the base fertilizer is evenly mixed with the soil to prevent root burning. Whether the height of backfill soil meets the requirements, so as to avoid trees shaking. Check and file according to the company's quality inspection standards.
Note: base fertilizer should be cooked and mixed with soil to prevent root burns.
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