Green building basement roof landscape greening structure and construction method

Abstract

The application discloses a kind of green building basement roof landscape greening structure and construction method, including successively laying drainage pipe, fine aggregate, geogrid, light aggregate and geotextile on the basement roof, the geotextile is filled with planting soil and slag, the planting soil is planted lawn and arbor on, and the planting soil thickness of planting lawn is greater than the planting soil thickness of planting arbor, and the slag is built landscape structure;Therefore, this basement roof landscape greening structure can stabilize each layer structure and facilitate construction, can also reduce and diffuse load, and eliminate stress concentration by load balance, avoid the basement roof to produce crack and seepage, also limit the pushing and sliding of light aggregate by the counterforce of tensile force generated by geogrid due to settlement elongation, ensure that landscape or greening vegetation is not damaged, so it has the advantages of reasonable structure, convenient construction, reliable quality, economic saving, energy saving and environmental protection, etc., combined with the corresponding construction method, it has high economic benefit and social benefit.

Description

Technical Field

[0001] This invention relates to the field of green building, and in particular to the landscape greening structure and construction method of the basement roof of a green building. Background Technology

[0002] The national standard GB / T 50378, "Evaluation Standard for Green Buildings," implemented on August 1, 2019, defines green buildings as: high-quality buildings that, throughout their entire life cycle, conserve resources, protect the environment, reduce pollution, provide people with healthy, suitable, and efficient living spaces, and maximize the harmonious coexistence of humans and nature. Green building materials are defined as building materials that, throughout their entire life cycle, reduce resource consumption, mitigate the impact on the ecological environment, and possess characteristics of energy conservation, emission reduction, safety and health, convenience, and recyclability.

[0003] Basement roof landscaping is a key component of green building, playing a vital role in increasing green space and improving the residential environment. However, existing basement roof landscaping systems suffer from problems such as low plant survival rates, poor growth, cracks in the landscaping structures, and water seepage. These issues require significant financial investment to address later, failing to achieve the desired results. The main reasons for these problems are: firstly, inadequate drainage systems, such as the use of water-retaining materials on the roof, which can lead to root rot and death during rainy seasons, particularly in southern regions; secondly, improper structural layer design, failing to consider the weight differences between the landscaping and greening plant types, resulting in uneven stress and displacement between the heavier landscaping and lighter greening layers, damaging the appearance and aesthetics; and thirdly, the significant weight difference between the plants and the landscaping structures leads to excessive stress concentration in the basement roof, causing cracks and water seepage. Therefore, the landscaping and greening project on the basement roof must adopt technical measures that are adapted to local conditions, simple to construct, safe and reliable, and properly design the engineering structure and adopt scientific construction methods. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a green building basement roof slab landscape greening structure and construction method that is rationally constructed, easy to construct, reliable in quality, economical, energy-saving and environmentally friendly.

[0005] The technical problem of this invention is solved by the following technical solution:

[0006] A green building basement rooftop landscaping structure includes laying drainage pipes, fine aggregate, geogrid, lightweight aggregate, and geotextile sequentially on the basement rooftop. Planting soil or quarry waste is then filled onto the geotextile. Turf and trees are planted on the planting soil, with the planting soil thickness for the turf being greater than that for the trees. A landscape structure is constructed on the quarry waste, forming a green landscape layer together with the turf and trees. The thickness of the planting soil, quarry waste, and lightweight aggregate below the green landscape layer is set according to the principle that, under the same ground elevation, their cumulative weights, including their respective subweights, are approximately equal, i.e., turf + planting soil + lightweight aggregate. The unit width self-weight is approximately equal to the unit width self-weight of trees + planting soil + lightweight aggregate, which is approximately equal to the unit width self-weight of landscaping + quarry waste + lightweight aggregate. When the thicknesses of the planting soil, quarry waste, and lightweight aggregate layers are different, they are connected to the lower layer by a slope. The geogrid is laid longitudinally and transversely along the top of the basement roof slab on the drainage pipes, and after being stretched and tightened, it is fixed to the edge of the area of ​​the landscape greening structure. When fine aggregate, lightweight aggregate, planting soil, or quarry waste is filled on the geogrid in sequence, each a×b geogrid cell enclosed by the longitudinally and transversely distributed drainage pipes will sink downward to form a basin-shaped settlement basin. The geogrid will generate tension due to the elongation caused by settlement, which plays a role in consolidating and stabilizing the landscape greening layer.

[0007] The lawns, trees, and landscape structures have different self-weights, resulting in varying forces on the bottom of the lightweight aggregate. This can easily lead to uneven stress on the greening layer, causing displacement due to mutual pushing. To simplify calculations, it is assumed that the lightweight aggregate consists of multi-level spherical particles of different sizes, continuously filled multiple times (i.e., multi-level continuous gradation). Filling is done step-by-step, ensuring the particle size of each spherical particle is no larger than the spacing between particles in the previous level, to achieve maximum compaction. Although the thickness of the planting soil, slag, and lightweight aggregate below the greening layer is set at the same ground elevation, based on the principle that their cumulative self-weights are roughly equal, the load in local areas is difficult to achieve complete balance due to limitations imposed by the strength of the basement roof slab and the filling height above it. Therefore, the load on the basement roof slab is divided into two categories: uniformly distributed load and uniformly distributed eccentric load. The uniformly distributed load refers to a load evenly distributed on the basement roof slab. The uniformly distributed eccentric load refers to the difference in self-weight load between adjacent lawns, trees, and landscape structures due to their different self-weights. q When the bottom of the spherical particles of lightweight aggregate is measured from the top of the largest diameter spherical particles in the second layer, a uniformly distributed eccentric load is applied. q At this time, the bottom layer of the spherical particles will experience horizontal displacement due to mutual pushing, meaning there will be relative horizontal displacement between the bottom of the lightweight aggregate spherical particles and the basement roof slab, leading to cracks and even localized collapse of the landscaping layer. When geogrids are laid on the longitudinal and transverse drainage pipes, under uniformly distributed loads or uniformly distributed eccentric loads... qUnder the action of the load, the geogrid will sink downward to form a settlement basin. It is difficult to accurately derive the analytical solution of the geogrid settlement basin surface. However, the range of the angle between any point in a×b of the geogrid settlement basin and the x-axis is determined, that is, the range of the direction angle of the geogrid tension is determined. The settlement basin surface can be approximated by a known function, and the maximum tension of the geogrid can be calculated from this. In order to simplify the calculation, the geogrid tension and the frictional resistance of the fine aggregate are simplified to the planar case. The calculation is carried out for two cases under uniformly distributed eccentric load: the spherical particles of the two-stage lightweight aggregate are arranged in a horizontal arrangement and the spherical particles of the two-stage lightweight aggregate are arranged in a staggered arrangement.

[0008] Formula 1: Calculation of horizontally arranged loads under uniformly distributed eccentric load

[0009]

[0010] Formula 2: Calculation of staggered arrangement under uniformly distributed eccentric load

[0011]

[0012] Formula 3: Calculation of the maximum tensile force of geogrid

[0013] If the settlement basin surface of the geogrid is approximately fitted with a quadratic parabola, the equation of the quadratic parabola with the center of each grid a×b of the longitudinal and transverse drainage pipes as the origin and the top surface of the basement as the x-axis or y-axis, and the maximum tensile force of the geogrid are calculated as follows in the longitudinal section xoz or the transverse section yoz.

[0014] 1. Parallel arrangement under uniformly distributed eccentric load

[0015]

[0016] visible or but

[0017] or

[0018]

[0019] The maximum value is

[0020] or

[0021] Minimum value is

[0022]

[0023] 2. Parallel arrangement under uniformly distributed eccentric load

[0024] Similarly, or ,but

[0025] or

[0026]

[0027] The maximum value is

[0028] or

[0029] Minimum value is

[0030]

[0031] Formula 4: Calculation of elongation of geogrid

[0032]

[0033] Formula 5: Strength and Elongation Requirements of Geogrids

[0034]

[0035] Similarly, the above two arrangements under uniformly distributed loads are also calculated using a similar method. As can be seen from Formulas 1 to 4, when it rains or when there is a lot of water, the friction coefficient between the geogrid and the fine aggregate is greatly reduced, and the tensile force of the geogrid will increase. This is the main reason why the landscape greening layer without geogrid on the existing longitudinal and transverse drainage pipes cracks or even collapses locally, and it also proves the necessity of setting geogrids in the landscape greening structure of the basement roof.

[0036] The meanings of the symbols in Formulas 1 through 5 are as follows:

[0037] D , D 1 , D 2 —The diameters of the first stage, the second stage, and the third stage, which are two stages of continuous filling with different sizes of lightweight aggregate spherical particles, are respectively: the diameter of the first stage, the diameter of the second stage arranged in a horizontal line, and the diameter of the second stage arranged in a staggered line. m ;

[0038] a, b —These represent the longitudinal center-to-center distance and the transverse center-to-center distance between the longitudinal and transverse drainage pipes, respectively. m ;

[0039] F —Outer diameter of the longitudinal and transverse drainage pipes, m ;

[0040] α , β , f—The base angle of the isosceles triangle formed by the lines connecting the center of one second-stage spherical particle and the centers of two first-stage spherical particles when the spherical particles of lightweight aggregate are arranged in a horizontal row. When lightweight aggregate spherical particles are arranged in a staggered pattern, what is the base angle of the isosceles triangle formed by the lines connecting the center of one second-level spherical particle to the centers of two first-level spherical particles? , rad ;

[0041] v 1y , v 2y —These represent the angles between the tangents at any point on the settlement basin surface of each geogrid cell in the longitudinal and transverse drainage pipes and the horizontal axis x. rad ;

[0042] q —The difference between the adjacent uniformly distributed loads on the top of the first-level and second-level spherical particles in the second layer of lightweight aggregate per unit width, starting from the bottom of the spherical particles. This value is determined by the type and variety of landscaping above it. kN / m 2 ;

[0043] m —The coefficient of friction between the geogrid and the fine aggregate can be obtained by consulting literature or through testing; it is dimensionless.

[0044] P 1Z , P 1y , P 2z , P 2y —These are the vertical reaction forces of the bottom layer of first-grade spherical particles on the left or right side of the first-grade spherical particles in the second layer of lightweight aggregate per unit width, when the top of the first-grade spherical particles in the second layer is subjected to a uniformly distributed eccentric load, and the first-grade and second-grade spherical particles are arranged in parallel or staggered arrangements. kN / m ;

[0045] t 1 , t 2 —When the top of the first-level spherical particles in the second layer of lightweight aggregate per unit width is subjected to a uniformly distributed eccentric load, the vertical reaction force on the left or right side of the largest diameter spherical particle at the bottom layer is considered as the frictional resistance between the fine aggregate and the geogrid, depending on whether the first-level and second-level spherical particles are arranged in a horizontal or staggered manner. kN / m ;

[0046] P 1sy , P 2sy —These represent the uniformly distributed eccentric loads applied to the tops of the first-level spherical particles in the second layer of lightweight aggregate per unit width, starting from the bottom of the spherical particles. q During operation, the geogrid's restraining reaction force on the bottom layer of first-level spherical particles, which are filled in parallel or staggered arrangements, is the tensile force acting on the geogrid. kN / m ;

[0047] P 1syzmax , P 1syhmax , P 2syzmax , P 2syhmax —These represent the uniformly distributed eccentric loads applied to the tops of the first-level spherical particles in the second layer of lightweight aggregate per unit width, starting from the bottom of the spherical particles. q When in operation, the maximum reaction force constrained by the geogrid on the longitudinal and transverse directions of the first-level and second-level spherical particles, which are arranged in a horizontal line, is the maximum tensile force on the geogrid. Similarly, the maximum reaction force constrained by the geogrid on the longitudinal and transverse directions of the bottom layer of first-level and second-level spherical particles, which are arranged in a staggered line, is the maximum tensile force on the geogrid. kN / m ;

[0048] P 1syzmin , P 2syhmin —These represent the uniformly distributed eccentric loads applied to the tops of the first-level spherical particles in the second layer of lightweight aggregate per unit width, starting from the bottom of the spherical particles. q When subjected to force, the minimum reaction force in the longitudinal and transverse directions of the geogrid is the minimum tensile force acting on the geogrid. kN / m ;

[0049] [ s — Permissible tensile strength of geogrid kN / m ;

[0050] Δl x , Δl y —These represent the elongation of the geogrid at half the length of each grid in the longitudinal drainage pipe and the elongation of the geogrid at half the length of each grid in the transverse drainage pipe, respectively. m ;

[0051] or , e x , ey —The elongation of the initial tightness of the geogrid is generally 0.5% to 1%, the longitudinal elongation of the geogrid and the transverse elongation of the geogrid are generally not greater than 3%, and are dimensionless.

[0052] [ e — Permissible elongation of geogrid, dimensionless.

[0053] The drainage pipe is a new type of green and environmentally friendly drainage plastic pipe with a corrugated shape, formed by adding other auxiliary agents to high-density polyethylene (HDPE). The inner diameter of the drainage pipe and the spacing and quantity of the longitudinal and transverse drainage pipes are determined by the drainage volume. Except for a certain height reserved at the bottom, the remaining part of the drainage pipe is perforated in a plum blossom pattern. The drainage pipe is wrapped with geotextile on all four sides. The reserved height at the bottom of the drainage pipe is determined according to the reserved water storage capacity after watering during the rainy or dry season in the local area, and is generally 3cm to 5cm.

[0054] The geogrid is a steel-plastic geogrid, made of high-strength steel wire that has undergone special treatment, combined with polyethylene or polypropylene and other additives, and extruded by injection molding to form a composite high-strength tensile strip. The joints are then welded using a reinforced bonding fusion welding technique to form a planar geosynthetic material. The tightness of the geogrid laid on the drainage pipe is controlled by an elongation rate of 0.5% to 1%. The maximum settlement of the settlement basin within each a×b grid of the longitudinal and transverse drainage pipes is less than or equal to the outer diameter of the drainage pipe, and the maximum elongation of the geogrid is not greater than 3%.

[0055] The fine aggregate is recycled fine particles made from crushed waste concrete blocks, with a mud content of 3% to 5% and a thickness of 3cm to 5cm. It is reserved within the bottom height of the drainage pipe as a reserve for water storage.

[0056] The lightweight aggregate is a lightweight recycled aggregate produced by foaming construction waste, biological sludge and fly ash in a rotary kiln. It has a spherical shape, a smooth and hard surface, and a honeycomb structure inside. The particle size of the lightweight aggregate is 5 mm to 20 mm, with a maximum particle size of 25 mm. The lightweight aggregate is connected at different filling heights by a slope with a gradient of 1:1.1 to 1:1.5.

[0057] The geotextile is a permeable geosynthetic material made of synthetic fibers through needle punching or weaving, and it is placed on top of lightweight aggregate.

[0058] The planting soil is suitable for planting lawns and trees.

[0059] The slag is a mixture of soil and rock after rock blasting.

[0060] A construction method for a green building basement roof landscaping structure includes the following steps:

[0061] Step 1: Draft a preliminary plan

[0062] 1. Develop a preliminary plan for the landscape greening structure based on the structure of the basement roof slab;

[0063] 2. Test the physical and mechanical properties of drainage pipes, planting soil, slag, lightweight aggregate, fine aggregate, geotextile and geogrid;

[0064] 3. Calculate, verify, and select the filling thickness and geogrid model and specifications for each layer of the landscape greening structure using Formulas 1 to 5;

[0065] Step 2: Filling Construction

[0066] 1. Clean up debris on the surface of the basement ceiling, mark out the construction area for landscaping and greening, install the longitudinal and transverse drainage pipes according to the design, straighten out the drainage system, and connect the ends of the longitudinal and transverse drainage pipes to the main pipe and connect to the municipal drainage network.

[0067] 2. Lay geogrids on the longitudinal and transverse drainage pipes. The geogrids should be flat and straight, and the tightness should be controlled according to the design requirements. The overlap of each geogrid joint should be 50cm to 100cm. After the geogrids are flattened and tightened, they should be fixed with soil nails at the junctions of the basement with other structures and at the edges of the landscape greening area. During construction, avoid construction machinery from directly running over the geogrids. The laying quality of the geogrids should be checked at any time during construction. If any damage such as breakage, puncture, or tearing is found, it should be replaced.

[0068] 3. Remove any sharp-edged or angular gravel and debris from the fine aggregate, and then spread the fine aggregate evenly.

[0069] 4. Fill with lightweight aggregate, compact and level it with an excavator bucket, and connect different filling heights with sloping sections; lay geotextile on the lightweight aggregate, ensuring the geotextile is flat and straight, with each overlap width greater than 30-50 cm. Avoid direct crushing of the geotextile by construction machinery during construction. Inspect the laying quality of the geotextile regularly during construction, and replace it if any damage such as folds, punctures, or tears is found.

[0070] Step 3: Fill with planting soil

[0071] 1. First, remove stones and debris from the planting soil to ensure a good soil environment for seedling growth;

[0072] 2. The construction process of planting soil consists of excavation, transportation, filling and compaction. Large-area site leveling is suitable for the use of large earthmoving machinery.

[0073] 3. Shape the planting soil according to the design requirements;

[0074] 4. Use some composite nutrient soil in the planting hole for trees to ensure that the seedlings grow vigorously after they survive;

[0075] Step 4: Filling the slag heap

[0076] 1. Determine the maximum particle size of the slag based on the total filling thickness. The maximum particle size shall not exceed one-half to two-thirds of the total thickness or the thickness of the layered filling, and the maximum particle size shall be 10cm to 15cm.

[0077] 2. Cover the joint with the geotextile with 3cm to 5cm of clay or medium to coarse sand without any gravel.

[0078] 3. Fill and level in layers, then compact with a road roller until the compaction meets the design requirements;

[0079] Step 5: Construction of Landscape Structures

[0080] Construction, quality inspection, and acceptance shall be carried out in accordance with relevant standards and specifications based on the characteristics of the landscape structures.

[0081] Step Six: Greenery Construction

[0082] 1. Select trees and grasses suitable for the local environment according to the design requirements, and ensure that their varieties, plant height and density meet the design requirements;

[0083] 2. Plant trees and lawns in accordance with the cultivation standards and specifications for various types of greening varieties, and carry out maintenance during the period of quality defects.

[0084] Compared with existing technologies, this invention provides a green building basement roof landscaping structure with the following main features: First, the thickness of the planting soil, slag, and lightweight aggregate below the landscaping layer is set according to the principle that their respective self-weights are basically equal. Where the thicknesses of the planting soil, slag, and lightweight aggregate layers are different, they are connected by a certain slope, which is beneficial to the stability of each layer, construction convenience, and load diffusion, thus improving the load-bearing capacity of the basement roof slab. Second, the use of lightweight recycled aggregate for laying reduces the basement load, maximizes load balance, and avoids excessive stress concentration in the basement roof slab, as well as cracks and water seepage. Third, in the longitudinal direction... When geogrids are laid on horizontal drainage pipes, and fine aggregates, lightweight aggregates, and planting soil or slag are sequentially filled on the geogrids, each a×b geogrid cell enclosed by the longitudinally and transversely distributed drainage pipes will settle downwards to form a settlement basin. The geogrids elongate due to settlement, generating tensile force. The reaction force of this tensile force, i.e., pressure, applied to it, prevents the overall structure from loosening and separating, and restricts the pushing and sliding of lightweight aggregates, thus ensuring that the landscape or green vegetation is not damaged, and also ensuring the quality and aesthetic appearance of the landscape greening. Fourth, it uses green and environmentally friendly recycled building materials, reflecting the environmental policy of carbon peaking and carbon neutrality. Fifth, the provided calculation formulas are theoretically sound, concise, and practical, effectively guiding engineering design and construction. Therefore, this invention is a green building basement roof slab landscape greening structure that is rationally constructed, convenient to construct, reliable in quality, economical, energy-saving, and environmentally friendly. Combined with appropriate construction methods, it has high economic and social benefits. Attached Figure Description

[0085] Figure 1 This is a schematic diagram of the structure of the present invention.

[0086] Figure 2 for Figure 1 AA cross-section view.

[0087] Figure 3 This is a stress diagram of a horizontally arranged lightweight aggregate and a geogrid under a uniformly distributed eccentric load.

[0088] Figure 4 This is a stress diagram of the staggered arrangement of lightweight aggregates and the geogrid under uniformly distributed eccentric load. Detailed Implementation

[0089] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0090] like Figure 1~Figure 4 As shown, 1. Basement roof slab, 2. Drainage pipe, 3. Geogrid, 4. Fine aggregate, 5. Lightweight aggregate, 6. Geotextile, 7. Planting soil, 8. Slag heap, 91. Lawn, 92. Tree, 93. Landscape structure.

[0091] A green building basement roof landscaping structure and construction method, the landscaping structure as follows: Figure 1 As shown, the main components include laying drainage pipes 2, geogrids 3, fine aggregates 4, lightweight aggregates 5, and geotextiles 6 sequentially on the basement roof slab 1. The geotextiles 6 used for planting lawns 91 are filled with the thickest layer of planting soil 7, the geotextiles used for planting trees 92 are filled with the next thickest layer of planting soil 7, and the geotextiles 6 used for setting up landscape structures 93 are filled with a thinner layer of slag 8 that is heavier and stronger. Then, according to the location layout, the corresponding lawns 91, trees 92, and landscape structures 93 are planted respectively, and the landscape structures, lawns, and trees together form a landscape greening layer.

[0092] The aforementioned basement roof slab 1 refers to the roof slab of the basement structure of a green building residential community. Landscape greening ancillary works are set on it, which is an important part of green building. It separates people and vehicles, beautifies the environment, highlights ecological benefits, and effectively improves living conditions.

[0093] The drainage pipe 2 is a new type of green and environmentally friendly drainage plastic pipe with a corrugated shape, formed by adding other auxiliary agents to high-density polyethylene (HDPE). The inner diameter of the drainage pipe and the spacing and quantity of the longitudinal and transverse drainage pipes are determined by the drainage volume. Except for a certain height reserved at the bottom, the remaining part of the drainage pipe is perforated in a quincunx pattern at certain intervals and diameters, and the outside of the pipe is wrapped with needle-punched geotextile. The reserved height at the bottom of drainage pipe 2 is determined according to the reserved water storage capacity after watering during the rainy or dry season in the local area, generally 3cm to 5cm, to retain water without reserving too much water and avoid root rot of green plants due to water immersion, which would affect their growth.

[0094] The aforementioned geogrid 3 is a steel-plastic geogrid, made of high-strength steel wire that has undergone special treatment, combined with polyethylene (PE) or polypropylene (PP) and other additives. It is extruded using an injection molding machine to form a composite high-strength tensile strip, and its joints are welded using a special reinforced bonding fusion welding technique to form a planar geosynthetic material. It features high strength, high load-bearing capacity, corrosion resistance, aging resistance, high friction coefficient, uniform pore size, convenient construction, and long service life, making it a green and environmentally friendly new building material. When laid on drainage pipes, the geogrid, in addition to its structural mechanical function, combines with fine aggregates and the unperforated portions of the drainage pipes to provide a certain water retention capacity.

[0095] The tightness of the geogrid 3 laid on the drainage pipe 2 is controlled by an elongation rate of 0.5% to 1%, so that after filling with lightweight aggregate, planting soil or slag and landscape greening structure, the maximum settlement of the settlement basin in each grid a×b of the longitudinal and transverse drainage pipes is less than or equal to the outer diameter of the drainage pipe, and the maximum elongation of the geogrid is not greater than 3%.

[0096] The fine aggregate 4 is recycled fine particles made from crushed waste concrete blocks, with a mud content of 3% to 5% and a thickness of 3cm to 5cm. It serves as a reserved water storage capacity within the pre-reserved height at the bottom of the drainage pipe 2. In addition to generating frictional resistance with the lightweight aggregate 5, it has a certain water retention capacity when combined with the geogrid and the pre-reserved non-perforated portion of the drainage pipe.

[0097] The lightweight aggregate 5 is a lightweight recycled aggregate produced by foaming construction waste, biological sludge, fly ash, etc. in a rotary kiln. It has a spherical shape, a smooth and hard surface, and a honeycomb-like internal structure, characterized by low density, low thermal conductivity, and high strength. The particle size of the lightweight aggregate is generally 5mm to 20mm, with a maximum particle size of 25mm. Different filling heights of the lightweight aggregate are connected by slopes with a gradient of 1:1.1 to 1:1.5.

[0098] The geotextile 6 is a permeable geosynthetic material made of synthetic fibers through needle punching or weaving. It has excellent filtration, isolation, reinforcement and protection functions, high tensile strength, good permeability, high temperature resistance, freeze resistance, aging resistance and corrosion resistance. It is set on the top of the lightweight aggregate to stably gather the lightweight aggregate and at the same time prevent fine particles of the planting soil from settling into the lightweight aggregate.

[0099] The slag 8 is a mixture of soil and rock after rock blasting. After compaction, it has a certain strength and density and serves as the foundation for landscape structures.

[0100] The lawn 91 is an artificially planted or maintained grassland that serves a greening and beautifying function. The lawn includes a suitable amount of flowers and shrubs. The tree 92 is a backbone tree species in the garden, which serves to define space, provide shade, prevent glare, and regulate the climate. Both tree 92 and lawn 91 are general terms for greening plants.

[0101] The landscape structures 93 are artificial landscapes, including landscape lights, stone sculptures, fountains, pools, flower beds, flower racks, pavilions, etc., which are a general term for facilities for residents' leisure, entertainment and viewing. Their weight is generally greater than that of green plants.

[0102] The thickness of the planting soil 7, quarry 8, and lightweight aggregate 5 below the landscape greening layer is set according to the principle that the cumulative self-weight of each layer, including its own weight below, is basically equal under the condition that the ground elevation is the same. That is, the self-weight of the unit width of (lawn + planting soil + lightweight aggregate) ≈ the self-weight of the unit width of (tree + planting soil + lightweight aggregate) ≈ the self-weight of the unit width of (landscape + quarry + lightweight aggregate). When the thickness of each layer of planting soil, quarry, and lightweight aggregate is different, they are connected to the lower layer with a certain slope, which is conducive to the stability of each layer structure, construction convenience, and load diffusion.

[0103] The geogrid 3 is laid horizontally and vertically on the top of the basement roof slab 1, stretched and tightened, and fixed at the edge of the landscape greening structure area. When fine aggregate 4, lightweight aggregate 5, planting soil 7 or slag 8 are sequentially filled on the geogrid 3, each a×b geogrid 3 enclosed by the horizontally and vertically distributed drainage pipes 2 will sink downward into a basin shape. The geogrid will generate tensile force due to the elongation caused by the settlement, which plays a role in consolidating and stabilizing the landscape greening layer. The reaction force of this tensile force, i.e., pressure, is applied to it to prevent the overall structure from loosening and separating, ensuring that the landscape or green vegetation is not damaged.

[0104] The lawn 91, trees 92, and landscape structures 93 have different self-weights, resulting in different forces exerted on the bottom of the lightweight aggregate 5. This can easily lead to uneven stress on the landscape or green layer, causing them to push and displace each other, damaging the appearance of the landscape or greenery, and affecting its quality and aesthetics. To simplify the calculation, it is assumed that the lightweight aggregate 5 consists of multi-level continuous gradation of spherical particles of different sizes, filled in multiple stages. Under the premise that the particle size of the filling spheres is no larger than the distance between the particles of the previous stage, the filling is carried out step by step to achieve maximum density.

[0105] Although the thickness of the planting soil 7, slag 8 and lightweight aggregate 5 below the landscape greening layer is set according to the principle that the cumulative weight of each of them, including their own weight below, is basically equal under the condition that the ground elevation is the same, the load in some areas is difficult to achieve a completely equal balance due to the limitations of the strength of the basement roof slab 1 and the filling height above the roof slab. Therefore, the load of the basement roof slab is divided into two categories: uniformly distributed load and uniformly distributed eccentric load.

[0106] The uniformly distributed load refers to the load on the basement roof slab 1 being evenly distributed. The uniformly distributed eccentric load refers to the difference in self-weight load between adjacent lawns 91, trees 92, and landscape structures 93 due to their different self-weight loads. q When the top of the second layer of lightweight aggregate spheres with the largest diameter, starting from the bottom of the spheres in lightweight aggregate 5, is subjected to a uniformly distributed eccentric load... q At that time, the bottom layer of the spherical particles will experience horizontal displacement due to mutual pushing, that is, the bottom of the lightweight aggregate spherical particles will experience relative horizontal displacement with the basement roof slab, which will lead to cracks or even local collapse damage to the landscape greening layer.

[0107] When geogrid 3 is laid on the longitudinal and transverse drainage pipes, under uniformly distributed load or uniformly distributed eccentric load... qUnder the action of the load, the geogrid 3 will sink downward to form a settlement basin. It is difficult to accurately derive the analytical solution of the geogrid settlement basin surface. However, the range of the angle between any point in a×b of the geogrid settlement basin and the x-axis is determined, that is, the range of the direction angle of the geogrid 3 tension is determined. The settlement basin surface can be approximated by a known function, and the maximum tension of the geogrid can be calculated from this. In order to simplify the calculation, the geogrid tension and the frictional resistance of the fine aggregate are simplified to the plane case. The calculation is carried out for two cases under the uniformly distributed eccentric load: the spherical particles of the two-stage lightweight aggregate are arranged in a horizontal row and the spherical particles of the two-stage lightweight aggregate are arranged in a staggered row.

[0108] Formula 1: Calculation of horizontally arranged loads under uniformly distributed eccentric load

[0109]

[0110] Formula 2: Calculation of staggered arrangement under uniformly distributed eccentric load

[0111]

[0112] Formula 3: Calculation of the maximum tensile force of geogrid 3

[0113] If the settlement basin surface of the geogrid is approximately fitted with a quadratic parabola, the following formula is obtained by calculating the quadratic parabola equation with the center of each grid a×b of the longitudinal and transverse drainage pipes 2 as the origin and the top surface of the basement as the x-axis or y-axis, and the maximum tensile force of the geogrid 3 in the longitudinal section plane xoz or the transverse section plane yoz.

[0114] 1. Parallel arrangement under uniformly distributed eccentric load

[0115]

[0116] visible or but

[0117] or

[0118]

[0119] The maximum value is

[0120] or

[0121] Minimum value is

[0122]

[0123] 2. Parallel arrangement under uniformly distributed eccentric load

[0124] Similarly, or ,but

[0125] or

[0126]

[0127] The maximum value is

[0128] or

[0129] Minimum value is

[0130]

[0131] Formula 4: Calculation of Elongation of Geogrid 3

[0132]

[0133] Formula 5: Strength and Elongation Requirements of Geogrid 3

[0134]

[0135] Similarly, the above two arrangements under uniformly distributed load are also calculated in a similar way. As can be seen from Formulas 1 to 4, when it rains or the amount of water is large, the friction coefficient between geogrid 3 and fine aggregate 4 is greatly reduced, and the tensile force of geogrid 3 will increase. This is the main reason why the landscape greening layer without geogrid 3 on the existing longitudinal and transverse drainage pipes cracks or even collapses locally, and it also proves the necessity of setting geogrids in the landscape greening structure of the basement roof.

[0136] The meanings of the symbols in Formulas 1 through 5 are as follows:

[0137] D , D 1 , D 2 —The diameters of the first stage, the second stage, and the third stage, which are two stages of continuous filling with different sizes of spherical particles of lightweight aggregate 5, are respectively: the diameter of the first stage, the diameter of the second stage arranged in parallel, and the diameter of the second stage arranged in staggered. m ;

[0138] a, b —These represent the longitudinal center-to-center distance and the transverse center-to-center distance between the two drainage pipes, respectively. m ;

[0139] F —Outer diameter of the longitudinal and transverse drainage pipes 2 m ;

[0140] α , β , f—The base angle of the isosceles triangle formed by the lines connecting the center of one second-stage spherical particle and the centers of two first-stage spherical particles when the spherical particles of lightweight aggregate 5 are arranged in a horizontal row. When lightweight aggregate spherical particles are arranged in a staggered pattern, what is the base angle of the isosceles triangle formed by the lines connecting the center of one second-level spherical particle to the centers of two first-level spherical particles? , rad ;

[0141] v 1y , v 2y —These represent the angles between the tangents at any point on the surface of the settlement basin of each geogrid cell in the longitudinal and transverse drainage pipes 2 and the horizontal axis x. rad ;

[0142] q —The difference between the adjacent uniformly distributed loads on the top of the first-level and second-level spherical particles in the second layer of lightweight aggregate 5 per unit width, starting from the bottom of the spherical particles. This value is determined by the type and variety of landscaping above it. kN / m 2 ;

[0143] m —The friction coefficient between geogrid 3 and fine aggregate 4 is obtained by consulting literature or through experiments and is dimensionless;

[0144] P 1Z , P 1y , P 2z , P 2y —These are the vertical reaction forces of the bottom layer of first-grade spherical particles on the left or right side of the first-grade spherical particles when the top of the second layer of first-grade spherical particles (starting from the bottom of the second layer of lightweight aggregate particles with a unit width of 5) is subjected to a uniformly distributed eccentric load, for both the first-grade and second-grade spherical particles arranged in parallel and staggered arrangements. kN / m ;

[0145] t 1 , t 2 —When the top of the first-level spherical particles in the second layer of lightweight aggregate 5 (measured from the bottom of the spherical particles per unit width) is subjected to a uniformly distributed eccentric load, the frictional resistance of the fine aggregate caused by the largest diameter spherical particle at the bottom layer, representing the vertical reaction force on the left or right side of the first-level and second-level spherical particles filling in parallel or staggered arrangements, is considered equivalent to the frictional resistance between fine aggregate 4 and geogrid 3. kN / m ;

[0146] P 1sy , P 2sy —The first-level spherical particles in the second layer of lightweight aggregate with a unit width of 5 are subjected to a uniformly distributed eccentric load, starting from the bottom of the spherical particles. q During operation, the geogrid's restraining reaction force on the bottom layer of first-level spherical particles, which are filled in a horizontal or staggered arrangement, is the tensile force on geogrid 3. kN / m ;

[0147] P 1syzmax , P 1syhmax , P 2syzmax , P 2syhmax —The first-level spherical particles in the second layer of lightweight aggregate with a unit width of 5 are subjected to a uniformly distributed eccentric load, starting from the bottom of the spherical particles. q When in operation, the maximum reaction force constrained by the geogrid on the longitudinal and transverse directions of the first-level and second-level spherical particles, which are arranged in a horizontal line, is the maximum tensile force on geogrid 3. The maximum reaction force constrained by the geogrid on the longitudinal and transverse directions of the bottom layer of first-level spherical particles, which are arranged in a staggered line, is also the maximum tensile force on geogrid 3. kN / m ;

[0148] P 1syzmin , P 2syhmin —The first-level spherical particles in the second layer of lightweight aggregate with a unit width of 5 are subjected to a uniformly distributed eccentric load, starting from the bottom of the spherical particles. q When in action, the minimum reaction force in the longitudinal and transverse directions of the geogrid, that is, the minimum tensile force on geogrid 3, kN / m ;

[0149] [ s — Permissible tensile strength of geogrid 3 kN / m ;

[0150] Δl x , Δl y —These represent the elongation of geogrid 3 at half the length of each grid of the longitudinal drainage pipe 2 and the elongation of geogrid 3 at half the length of each grid of the transverse drainage pipe 2, respectively. m ;

[0151] or , ex , e y —The elongation of the initial tightness of the geogrid is generally 0.5% to 1%, the longitudinal elongation of the geogrid and the transverse elongation of the geogrid are generally not greater than 3%, and are dimensionless.

[0152] [ e — Allowable elongation of geogrid 3, dimensionless.

[0153] The specific construction steps for the green building basement roof landscaping structure are as follows:

[0154] Step 1: Draft a preliminary plan

[0155] 1. Based on the structure of the basement roof slab 1, formulate a preliminary plan for the landscape greening structure;

[0156] 2. Test the physical and mechanical properties of drainage pipe 2, planting soil 7, slag 8, lightweight aggregate 5, fine aggregate 4, geotextile 6 and geogrid 3.

[0157] 3. Calculate, verify, and select the filling thickness of each layer of the landscape greening structure and the model and specifications of geogrid 3 using formulas 1 to 5;

[0158] Step 2: Filling Construction

[0159] 1. Clean up debris from the surface of the basement ceiling slab 1, mark out the construction area for landscaping and greening, install the longitudinal and transverse drainage pipes 2 according to the design, straighten out the drainage system, and connect the ends of the longitudinal and transverse drainage pipes to the main pipe and connect to the municipal drainage network.

[0160] 2. Lay geogrid 3 on the longitudinal and transverse drainage pipes 2. The geogrid should be flat and straight, and the tightness should be controlled according to the design requirements. The overlap of each geogrid joint should be 50cm~100cm. After the geogrid 3 is flattened and tightened, it should be fixed with soil nails at the junction of the basement and other structures, as well as at the edge of the landscape greening structure area. During construction, avoid construction machinery from directly rolling on the geogrid. During construction, check the laying quality of the geogrid at any time. If any damage such as breakage, puncture, or tear is found, it should be replaced.

[0161] 3. Remove any sharp-edged or angular gravel and debris from fine aggregate 4, and then spread the fine aggregate evenly.

[0162] 4. Fill with lightweight aggregate 5, compact and level it with an excavator bucket, and connect different filling heights with sloping sections; lay geotextile 6 on the lightweight aggregate, the geotextile should be flat and straight, and the overlap width of each piece should be greater than 30 cm to 50 cm. During construction, avoid construction machinery directly rolling on the geotextile. During construction, check the laying quality of the geotextile at any time. If any damage such as folds, punctures, or tears is found, it should be replaced.

[0163] Step 3: Fill with planting soil

[0164] 1. First, remove stones and debris from the planting soil to ensure a good soil environment for seedling growth;

[0165] 2. The planting soil 7 consists of construction processes such as excavation, transportation, filling and compaction. For large-area site leveling, it is suitable to use large earthmoving machinery, such as large excavators.

[0166] 3. Shape the topography of planting soil 7 according to design requirements;

[0167] 4. Use some composite nutrient soil in the planting hole for trees to ensure that the seedlings grow vigorously after they survive;

[0168] Step 4: Filling the slag heap

[0169] 1. Determine the maximum particle size of the slag 8 based on the total filling thickness. The maximum particle size shall not exceed one-half to two-thirds of the total thickness or the layered filling thickness, and the maximum particle size shall be 10cm to 15cm.

[0170] 2. Cover the joint with geotextile 6 with 3cm~5cm of clay or medium-coarse sand without any gravel;

[0171] 3. Fill and level in layers, then compact with a road roller until the compaction meets the design requirements;

[0172] Step 5: Construction of Landscape Structures

[0173] Construction, quality inspection, and acceptance shall be carried out in accordance with relevant standards and specifications based on the characteristics of landscape structure 93.

[0174] Step Six: Greenery Construction

[0175] 1. Select 92 trees and flowers suitable for the local environment according to the design requirements, and ensure that the varieties, plant height and density meet the design requirements;

[0176] 2. Plant trees 92 and lawns 91 in accordance with the cultivation standards and specifications for various types of greening varieties, and carry out maintenance during the period of quality defects.

Claims

1. A green building basement roof deck landscape greening structure, characterized by The landscape greening structure comprises a drainage pipe (2), fine aggregate (4), geogrid (3), light aggregate (5) and geotextile (6) laid on the basement roof (1) in sequence, and the geotextile is filled with planting soil (7) or slag (8); the planting soil (7) is planted with lawn (91) and trees (92), and the thickness of the planting soil (7) for planting lawn (91) is greater than that for planting trees (92); the slag (8) is built with landscape structures (93), and the landscape structures, lawn (91) and trees (92) jointly form a landscape greening layer; the thicknesses of the planting soil (7), slag (8) and light aggregate (5) below the landscape greening layer are set according to the principle that the cumulative self-weights of each layer are basically equal under the condition that the ground elevations are the same, i.e. the unit width self-weight of lawn + planting soil + light aggregate ≈ the unit width self-weight of trees + planting soil + light aggregate ≈ the unit width self-weight of landscape + slag + light aggregate, wherein the thicknesses of each layer of the planting soil (7), slag (8) and light aggregate (5) are different, and the interfaces between the layers are connected by slopes; the geogrid (3) is laid on the drainage pipe (2) along the top of the basement roof (1) in a longitudinal and transverse manner, and is fixed at the edges of the area of the landscape greening structure after being stretched flat, and when the fine aggregate (4), light aggregate (5), planting soil (7) or slag (8) is filled on the geogrid (3) in sequence, each a×b geogrid (3) surrounded by the longitudinally and transversely distributed drainage pipe (2) will form a basin-shaped settlement basin that sinks downward, and the geogrid (3) will generate a pulling force due to the settlement elongation to condense and stabilize the landscape greening layer; the self-weights of the lawn (91), trees (92) and landscape structures (93) are different, and the forces generated on the bottom of the light aggregate (5) are different, which can easily lead to uneven stress of the landscape greening layer and displacement caused by mutual pushing and pulling, and in order to simplify the calculation, it is assumed that the light aggregate (5) is a plurality of levels of spherical particles with different sizes for multiple continuous filling, i.e. multiple continuous gradation, and the filling is performed step by step under the premise that the particle size of the spherical particles is not greater than the gap distance of the previous level of spherical particles, so as to achieve the maximum density; although the thicknesses of the planting soil (7), slag (8) and light aggregate (5) below the landscape greening layer are set according to the principle that the cumulative self-weights of each layer are basically equal under the condition that the ground elevations are the same, due to the limitation of the strength of the basement roof (1) and the filling height above the basement roof, the local area load is difficult to achieve complete equality and balance, and therefore the load of the basement roof (1) is divided into two types of uniform load and uniform partial load; the uniform load refers to the load received by the basement roof (1) which is uniformly distributed, and the uniform partial load refers to the difference between the self-weight loads of two adjacent interfaces of the lawn (91), trees (92) and landscape structures (93) due to the different self-weight loads of the two q ; when the bottom of the spherical particles of the light aggregate (5) is calculated to the top of the second layer of the maximum diameter spherical particles, the uniform partial load q At this time, the first layer of the bottom of the spherical particles will produce mutual horizontal displacement, that is, the bottom of the spherical particles of the lightweight aggregate and the top of the basement will have relative horizontal displacement, and cause the landscape green layer to crack and even partially collapse; when the geogrid (3) is laid on the vertical and horizontal drainage pipes, under the action of uniform load or uniform eccentric load q It is difficult to accurately derive the analytical solution of the geogrid settlement basin curve, but the angle range between any point in the a×b of the geogrid settlement basin and the x-axis is determined, that is, the direction angle range of the geogrid tension is determined, and the maximum tension of the geogrid (3) is calculated by approximating the settlement basin curve with a known function; in order to simplify the calculation, the frictional resistance of the geogrid tension and the fine aggregate (4) is simplified as a plane, and two cases are calculated, that is, the horizontal arrangement of the two-stage lightweight aggregate spherical particles under the action of uniform eccentric load and the staggered arrangement of the two-stage lightweight aggregate spherical particles. Formula one: the calculation of the flat arrangement under the action of uniform partial load Formula two: the calculation of the staggered arrangement under the action of uniform partial load Formula three: the maximum tension calculation of the geogrid (3) Approximately fitting the settlement basin curve of the geogrid with a quadratic parabola, in the longitudinal section plane xoz or the transverse section plane yoz, taking the center of each a×b grid of the longitudinal and transverse drainage pipes (2) as the origin and the basement top surface as the x-axis or y-axis quadratic parabola equation and the maximum tension calculation of the geogrid (3) are as follows: ① The flat arrangement under the action of uniform partial load visible or then or maximum value is or The minimum is ② The staggered arrangement under the action of uniform partial load By analogy, or then or The maximum value is or The minimum value is Formula four: the elongation calculation of the geogrid (3) Formula five: the strength and elongation requirements of the geogrid (3) Similarly, the above two arrangements under the action of uniform load are also calculated by similar methods. As can be seen from formula one to formula four, when it rains or the water quantity is large, the friction coefficient between the geogrid (3) and the fine aggregate (4) is greatly reduced, and the tension of the geogrid (3) will increase. This is the main reason why the landscape green layer on the existing longitudinal and transverse drainage pipes without geogrid (3) cracks and even partially collapses, and it also proves the necessity of setting the geogrid in the basement top plate landscape green structure; The meanings of the symbols in formula one to formula five are as follows: D, D 1 、D 2 - the first level diameter, the second level diameter in a straight arrangement and the second level diameter in a staggered arrangement for two levels of different spherical particle sizes of the lightweight aggregate (5) respectively, m ; a 、b - the longitudinal and transversal center-to-center distances between the longitudinal and transversal drain pipes (2), respectively, m ; Φ - the outer diameter of the longitudinal and transversal drain (2), m ; α , β , φ - the angle of the base angle of the isosceles triangle formed by the line connecting the center of a second-level spherical particle with the centers of two first-level spherical particles when the spherical particles of the lightweight aggregate (5) are arranged in a parallel alignment - the angle of the base angle of the isosceles triangle formed by the line connecting the center of a second-level spherical particle with the centers of two first-level spherical particles when the spherical particles of the lightweight aggregate are arranged in a staggered alignment , rad ; v 1y 、v 2y — the angle between the tangent at any point on the curved surface of the settlement basin and the horizontal axis x, respectively, rad ; q - the difference in the uniform load received by the bottom of the spherical particles of the second layer of the first and second level of the spherical particles of the unit width lightweight aggregate (5) from the top of the spherical particles, the value of which is determined by the type of landscape greening and the type of greening on it, kN / m 2 ; μ - the friction coefficient between the geogrid (3) and the fine aggregate (4), obtained by consulting the literature or by testing, dimensionless; P 1Z 、 P 1y 、 P 2z 、 P 2y — the vertical reaction force of the bottommost first-level spherical particle on the left side or the right side when the second layer of first-level spherical particles and second-level spherical particles arranged in a horizontal row are filled, and the second layer of first-level spherical particles and second-level spherical particles arranged in a staggered row are filled, respectively, from the bottom of the spherical particle of the unit width lightweight aggregate (5), with the top of the first-level spherical particle of the second layer subjected to a uniformly distributed eccentric load, kN / m ; τ 1 、 τ 2 - the fine aggregate frictional resistance caused by the left or right vertical reaction force of the maximum diameter of the bottom layer of the spherical particles of the first level and the second level spherical particles when the second layer of the first level spherical particles is subjected to the uniform bias load from the bottom of the spherical particles of the unit width lightweight aggregate (5), respectively, is equivalent to the frictional resistance between the fine aggregate (4) and the geogrid (3), kN / m ; P 1sy 、 P 2sy - the tensile force of the geogrid (3) when the second layer of first grade spherical particles on the bottom of the unit width lightweight aggregate (5) is subjected to a uniformly distributed eccentric load from the top of the first grade spherical particles q , the tensile force of the geogrid (3) when the second layer of first grade spherical particles on the bottom of the unit width lightweight aggregate (5) is subjected to a uniformly distributed eccentric load from the top of the first grade spherical particles kN / m ; P 1syzmax , P 1syhmax , P 2syzmax , P 2syhmax —The top of the first-level spherical particles in the second layer of lightweight aggregate (5) per unit width are subjected to a uniformly distributed eccentric load, starting from the bottom of the spherical particles. q When in action, the maximum reaction force of the geogrid constrained by the first-level spherical particles and the second-level spherical particles arranged in parallel filling along the longitudinal and transverse directions is the maximum tensile force on the geogrid (3). The maximum reaction force of the geogrid constrained by ... kN / m ; P 1syzmin , P 2syhmin - the minimum tensile force on the geogrid (3) when the second layer of first grade spherical particles of the bottom of the spherical particles of the unit width lightweight aggregate (5) is subjected to a uniformly distributed eccentric load from the top of the first grade spherical particles, respectively, q - the minimum tensile force on the geogrid (3) when the second layer of first grade spherical particles of the bottom of the spherical particles of the unit width lightweight aggregate (5) is subjected to a uniformly distributed eccentric load from the top of the first grade spherical particles, respectively, kN / m ; σ the allowable tensile force of the geogrid (3), kN / m ;​ Δl x 、 Δl y - the elongation of the geogrid (3) per half length of the longitudinal drain (2) and the elongation of the geogrid (3) per half length of the transverse drain (2), respectively, m ; η 、 ε x 、 ε y The initial tightness of the geogrid (3) is generally 0.5%-1%, and the longitudinal and transverse elongations of the geogrid are generally not greater than 3%. [ ε ] - the allowable elongation of the geogrid (3), dimensionless.

2. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The drainage pipe (2) is a new type of green and environmentally friendly drainage plastic pipe material formed by adding other auxiliary agents to high-density polyethylene (HDPE) and having a corrugated shape. The inner diameter and the longitudinal and transverse drainage pipe arrangement spacing a, b and the number of the drainage pipe are determined by the drainage capacity. Except that a certain height is reserved at the bottom of the drainage pipe, the rest of the periphery is provided with a plum blossom-shaped punching, and the four peripheries outside the drainage pipe are wrapped with geotextile. The reserved height at the bottom of the drainage pipe is determined according to the reserved water storage capacity after watering during the rainy season or the dry season in the place.

3. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The geogrid (3) is a steel-plastic geogrid. High-strength steel wire is treated in a special way, combined with polyethylene or polypropylene and added with other auxiliary agents, extruded into a composite high-strength tensile strip by an injection molding machine, and then the intersection points are welded by a strengthened bonding welding technology to form a planar geotechnical material. The tightness of the geogrid (3) laid on the drainage pipe (2) is controlled at an elongation of 0.5% to 1%, the maximum settlement of the settlement basin in each a×b grid of the longitudinal and transverse drainage pipes is less than or equal to the outer diameter of the drainage pipe, and the maximum elongation of the geogrid is not greater than 3%.

4. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The fine aggregate (4) is a recycled fine particle formed by crushing waste concrete blocks, with a clay content of 3% to 5% and a thickness of 3cm to 5cm.

5. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The lightweight aggregate (5) is a lightweight recycled aggregate produced by foaming building waste, biological sludge and fly ash in a rotary kiln, and has a spherical shape, a smooth and hard surface and a honeycomb structure. The particle size of the lightweight aggregate is 5mm to 20mm, and the maximum particle size is 25mm. The lightweight aggregate at different filling heights is connected by a slope with a slope of 1:1.1 to 1:1.

5.

6. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The geotextile (6) is a water permeable geosynthetic material made of synthetic fibers by needling or weaving, and the geotextile is arranged on the upper part of the lightweight aggregate.

7. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The planting soil (7) is soil suitable for planting lawns and growing trees.

8. The green roof deck landscape structure for a basement of a green building according to claim 1, characterized in that The spoil (8) is a mixture of soil and stone after stone blasting.

9. A construction method of a green building basement roof deck landscape greenery structure according to claim 1, characterized in that The construction method comprises the following steps: Step one, preliminary scheme S1. According to the structure of the basement roof (1), a preliminary scheme of landscape greening structure is formulated; S2. Test and detect the physical and mechanical indexes of the drainage pipe (2), the planting soil (7), the spoil (8), the lightweight aggregate (5), the fine aggregate (4), the geotextile (6) and the geogrid (3); S3. Calculate and check the filling thickness of each layer of the landscape greening structure and the model and specification of the geogrid (3) according to the formulas one to five; Step two, filling construction S1. Clean the surface of the basement roof (1) of sundries, lay out the construction range of landscape and greening, arrange the longitudinal and transverse drainage pipes (2) according to the design, straighten the drainage system, and connect the ends of the longitudinal and transverse drainage pipes into the total pipe and into the municipal drainage pipe network; S2. Lay the geogrid (3) on the longitudinal and transverse drainage pipes (2), and require the geogrid to be flat and straight, and control the tightness according to the design requirements, overlap the joints of each geogrid by 50cm~100cm, fix the geogrid (3) with soil nails after pulling it flat and tight at the junctions of the basement and other structures, and at the edges of the landscape greening structure area, avoid directly rolling the construction machinery on the geogrid during construction, and check the laying quality of the geogrid at any time during construction, and replace the damaged geogrid if it is damaged by folding, piercing or tearing; S3. Remove the sharp-edged stones from the fine aggregate (4), and evenly lay the fine aggregate; S4. Fill the lightweight aggregate (5), and use the excavator bucket to tap and flatten, and use slopes to connect at different filling heights; S5. Lay the geotextile (6) on the lightweight aggregate, and make the geotextile flat and straight, and overlap each geotextile by more than 30㎝~50㎝, avoid directly rolling the construction machinery on the geotextile during construction, and check the laying quality of the geotextile at any time during construction, and replace the damaged geotextile if it is damaged by folding, piercing or tearing; Step three, filling planting soil S1. First, remove the stones from the planting soil (7) to ensure a good soil environment for the growth of seedlings; S2. The planting soil (7) is composed of the construction processes of excavation, transportation, filling and compaction, and large-scale site leveling is suitable for large-scale earthwork machinery construction; S3. According to the design requirements, the topography of the planting soil (7) is shaped; S4. Use part of the composite nutrient soil at the planting tree hole to ensure the vigorous growth of the seedlings after they survive; Step four, filling spoil S1. Determine the maximum particle size of the spoil (8) according to the total filling thickness, and the maximum particle size should not be greater than one half to two thirds of the total thickness or the filling thickness of each layer, and the maximum particle size is 10cm~15cm; S2. Cover 3cm~5cm of clay or medium-coarse sand without admixture of stones at the joint with the geotextile (6); S3. Fill and flatten in layers, and use a road roller to compact and densify, and the density meets the design requirements; Step five, landscape structure construction According to the characteristics of the landscape structure (93) by relevant standard specification construction, quality inspection and acceptance; Step six, green construction S1. According to the design requirements, select suitable local environment trees (92) and flowers that make up the lawn (91), the variety, plant height and density meet the design requirements; S2. According to the cultivation standards of various types of green varieties, plant trees (92) and lawn (91), and carry out quality defect period maintenance.

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