6 Landscape and Greening in Code for Design of Highway Environmental Protection

6. 1. 1 The landscape and greening design scope mentioned in the highway environmental protection design is limited to the highway land boundary. When the landscape and greening engineering design on both sides of the highway must occupy land outside the normal land use range, the occupied land should be counted as highway land. In the route selection and design of highways, especially expressways, we should consciously bring the existing natural or human landscapes outside the scope of highway land into the visual scope and use them to integrate highways with natural and human landscapes. This chapter stipulates the utilization and improvement of the environment in highway construction, mainly for expressways and sections with landscape requirements.

6. 1.2 Highway landscape design should take highway main works, namely highway alignment, bridges, tunnels, interchanges and facilities along the line, as the system domain of comprehensive buildings, and adopt technical countermeasures suitable for natural environment and economic conditions. We can't ignore local conditions and engineering characteristics, blindly increase investment in order to pursue landscape effect unilaterally, and we can't ignore landscape design without combining engineering characteristics, resulting in disharmony between highway and natural landscape.

6.2 landscape

6.2. 1 Highway landscape design should systematically consider the landscape of the highway itself and the existing landscape along the route, so that they can coordinate with each other and form a harmonious landscape zone, which not only provides comfortable driving environment for highway users, but also makes people who observe the highway environment from outside the highway feel that the highway landscape is in harmony with the surrounding environment.

6.2.2 Highway landscape design is only one aspect of the highway itself, and it is necessary to make full use of the landscape along the route.

Service area is the most concentrated place for highway users' activities, and the demand for landscape is also strong, so the location and layout of service area should make full use of the distinctive natural landscape.

6.2.3 From the perspective of engineering technology and economy, the excavation depth is more than 25m, and the fill height is more than 20m, that is, deep excavation and high fill sections, so the schemes of setting tunnels and bridges should be compared respectively.

6.2.4 Setting billboards and billboards on both sides of the expressway will distract drivers, thus easily causing traffic accidents. Therefore, billboards and billboards (except toll stations, service areas, starting points and ending points) shall not be set up within the scope of highway land use.

Billboards and billboards generally refer to brands used for commercial, political, publicity and other purposes except street signs. Because architectural sketches may distract drivers, it is not recommended to use them on highway sections.

6.3 greening

6.3. 1 The purpose of highway greening is to alleviate various impacts caused by highway construction and operation, protect the natural environment, improve the living environment, and improve the safety and comfort of highway traffic. Highway greening design must adapt to regional characteristics and natural environment, and reasonably determine the location, scope and tree species of greening.

Different countries and regions have different classifications of the functions of highway greening. The classification method represented by Japan is to divide greening into three functions: safe driving, beautification and environmental protection, so as to determine the types and scale of greening planting. In fact, the greening planting mode determined by one function often has many functions, such as guiding the driver's sight, guiding and judging the direction of highway alignment, etc. It not only has the sight guiding function in traffic engineering, but also has the ability to protect the environment along the way and beautify the landscape. Therefore, this specification divides the highway greening function into two categories: "improving the environment" and "protecting the environment" from the analysis of the actual effect and expected purpose of greening planting. In the design, the planting type should not be determined unilaterally and in isolation according to certain needs, but the different effects of a planting type should be comprehensively considered and rationally utilized.

6.3.2 In order to protect the environment, firstly, protect the driving of the highway itself from snow or reduce the impact; Secondly, prevent and control the pollution of waste soil, noise and waste gas to the environment along the road during construction and operation.

6.3.2.1~ Shelterbelt and gas pollution prevention forest belt in 6.3.2.2 involve the width of land, so in the design process, basic data such as meteorology and land resources should be fully investigated to ensure that the design is economical and reasonable.

6.3.3 Various planting patterns for improving environmental greening do not affect the performance of the highway itself, and their purpose is to provide improved driving environment for drivers and passengers and promote driving safety.

Graves, slaughterhouses and garbage dumps near the expressway pollute the vision and affect the mood. The visual environment should be improved by sheltering and planting.

6.3.4 Appropriate highway greening design will have a strong environmental effect. The planting modes under different functional conditions specified in this specification are designed to adapt to the various conditions in the areas where the highway passes, and to assemble the landscape belt along the highway through various planting points or sections, so as to be in harmony with the surrounding environment.

The greening design of interchange and service area should be coordinated with the local urban greening style and architectural style. This specification stipulates that landscape design should be done, and the aesthetic requirements of greening should be comprehensively considered on the basis of functional greening design to improve the level of greening design.

6.3.5 Plants commonly used in highway greening include evergreen trees, deciduous trees, evergreen shrubs and small trees, deciduous shrubs and small trees, vines and other plants. Tables 3 ~ 7 list the relevant plant classifications for designers' reference.

Evergreen tree table 3

The influence of the height (m) of the growing environment in the growing area on environmental pollution.

Temperature, humidity, sunny soil

Podocarpus belongs to sandy acidic soil of warm wetlands in East China and South China 16-25, which is a garden tree species with strong anti-pollution and sulfur dioxide resistance.

Pinus bungeana is a positive tree species in Northwest China, North China and Southwest China. It is slightly tolerant to semi-negative acidic or neutral loess, and fertile calcareous soil 25-30 has strong resistance to soot and sulfur dioxide. It's tree-shaped and green.

Pinus tabulaeformis in North China, Northeast China and Northwest China are all sunny. Resistant to 25-30% dust and wind in saline-alkali, moisture-proof, drought-resistant, acid-resistant or neutral soil, vulnerable to sulfur dioxide damage to landscape trees.

Yun Song North China and Northwest China like cold, cool and humid climate, and slightly acidic soil 20 is pollution-resistant and has good dust absorption and noise reduction capabilities.

Platycladus orientalis in North China, East China and South China likes sunshine and grows well at 8℃- 16℃. Pollution-resistant garden trees in 20 different soils.

Pines and cypresses in North China, East China and Sichuan are fond of sunshine, drought-resistant and heat-resistant, and have the functions of vacuuming and noise reduction.

Longbai Yangtze River and Yellow River basins are sunny, warm and humid, and Runtu 8 is a landscape tree with the functions of anti-pollution, dust absorption and noise reduction.

Eucalyptus in East China, South China and Southwest China likes light, and the climate is acidic or slightly alkaline. Lime soil 38 has moderate anti-pollution ability, dark green leaves and round crown.

The acidic soil 15-20 in sunny, warm and rainy climates in East China, Southwest China and North China is pollution-resistant, can absorb toxic substances in the air, and has a broad crown.

Betula platyphylla enjoys sunshine in East China and Southwest China. Acidic soil with warm and humid climate has strong anti-pollution ability and absorbs harmful substances in the air.

Deciduous tree table 4

The influence of the height (m) of the growing environment in the growing area on environmental pollution.

Temperature, humidity, sunny soil

Metasequoia glyptostroboides enjoys sunshine, warm and humid climate, fertile sandy soil, weak sulfur dioxide resistance of slightly acidic soil 30-40, and good noise reduction effect.

The acid sandy soil in the Yangtze River valley of Chichimatsu has weak resistance to sulfur dioxide, straight trunk and conical crown.

Betula platyphylla likes sunshine and cold-resistant acidic soil in northern and plateau areas, and has strong adaptability. The crown of 15 is rectangular.

Populus tomentosa enjoys 20-30 days of sunshine and humid climate, which can resist pollution, absorb harmful substances in the air and absorb dust.

Willow bears drought, likes water and sunshine. The sand with good air permeability is resistant to smoke and dust, can absorb harmful substances in the air, and has sand-fixing ability.

The sandy soil 15 with cold resistance, sunny, strong adaptability and good ventilation in the northern area of steamed bread willow is resistant to smoke and dust.

The weeping willows in the Yangtze River valley, North China and Shaanxi are fond of sunshine and have strong adaptability. Wet sandy soil 18 is anti-pollution and can adsorb harmful substances.

Yushu enjoys sunshine all over the country, strong adaptability, fertile and moist soil, pollution resistance, smoke resistance and dust retention.

The southern area of Fengyang enjoys sunshine, and the humid climate is fertile and profound. Oily sandy soil, acidic and weakly alkaline soil are resistant to pollution.

Sophora japonica is a sandy soil with sunshine all over the country, dry and cold resistance and good drainage. 10- 15 resists pollution and absorbs harmful gases.

Robinia pseudoacacia likes sunshine all over the country, and it is drought-tolerant, shade-tolerant and waterlogging-tolerant. Sandy soil with good drainage has strong anti-pollution ability, and absorbs harmful substances and dust.

Ailanthus altissima likes the sunshine all over the country and has strong adaptability. 20-30 has weak resistance to dust and sulfur dioxide, can absorb dust and has good noise reduction effect.

The fertile sandy soil in the northern area of poplar enjoys sunshine, cold and drought tolerance, and strong resistance to sulfur dioxide.

The provinces south of the 500 Yellow River like sunshine, but they are not tolerant of shade. The soil 15 with deep, humid and well-drained climate has strong resistance to sulfur dioxide and nitrogen dioxide dust, with spherical crown and purple autumn leaves.

Paulownia northeast, north China, northwest China, east China and other places like sunshine, no shade, warm climate, drought resistance, no tolerance to stagnant water and saline-alkali humidity, fertile and loose soil, good ventilation, smoke and dust resistance, and can absorb harmful substances in the air.

Ash trees like the light, warm and humid climate and calcareous soil all over the country. It can also grow in alkaline and neutral soil. 15 has strong smoke and dust resistance and sulfur dioxide resistance. The leaves in autumn are yellow.

Hopeful light in North China, Sichuan and the south of the Yangtze River can adapt to various climatic conditions. Not cold-resistant and waterlogging-resistant, and not strict with soil requirements. Arid and barren sandy soil can be polluted by 15, which can improve soil and fix sand. The crown is flat and wide, with pink flowers in midsummer.

Evergreen shrubs and small trees Table 5

The influence of the height (m) of the growing environment in the growing area on environmental pollution.

Temperature, humidity, sunny soil

Buxus macrophylla in the Yangtze River basin and its south area has abundant sunshine, fertile, warm and humid climate, and the moist soil 1-3 has strong anti-pollution ability and absorbs harmful substances.

Bamboo and peach enjoy a warm and humid climate in the south of North China, which has strong anti-pollution ability and absorbs harmful substances.

Ligustrum lucidum enjoys sunshine in North China, Northwest China and Southwest China, and its climate is humid and fertile. Moist soil 13 can resist pollution, absorb harmful gases and dust.

Pittosporum enjoys sunshine in the south of the Yangtze River, and the warm and humid climate moistens the soil. It resists pollution and absorbs harmful substances.

Holly 1-3 national anti-pollution

Deciduous shrubs and small trees Table 6

The influence of the height (m) of the growing environment in the growing area on environmental pollution.

Temperature, humidity, sunny soil

Taiping flower is a light-loving, drought-tolerant, fertile and well-drained soil in North China. Absorb dust and harmful gases, anti-pollution flowers are milky white and bloom in May-June.

The warm climate in North China, Northwest China, East China and Southwest China is not strict with soil and has good resistance to organic matter. Flowers bloom in May-10.

Spring in East China, North China and Southwest China likes moist, cold-resistant, drought-tolerant and adaptable fertile soil. Anti-pollution flowers are light yellow and bloom in February-April.

Hibiscus enjoys the warm and humid acidic soil in China, but the requirements are not strict. 5. Anti-pollution flowers are white or purple and bloom from June to September.

The northeast, north and northwest flowers of Rosa roxburghii are pale yellow in sunny, cold-resistant, drought-resistant and well-drained acid soil, and bloom in April-May.

North China, such as Sophora japonica, likes sunshine, with humid climate and fertile soil. The crown of the tree is umbrella-shaped, and the branches droop like African claws.

The northeast, north and northwest of Amorpha fruticosa like sunshine, and the soil with good cold tolerance and drainage is resistant to pollution and absorbs harmful gases. These flowers are deep purple.

Small crown flower has strong adaptability, drought tolerance, adaptability to alkaline soil and developed anti-pollution root system all over the country. It is suitable for planting on embankment slopes on both sides of highways, with many colors and long flowering period.

The south of the Yellow River is light-loving, drought-resistant and trampling-resistant, and has strong adaptability to soil. Developed root system, suitable for lawn formation.

Velvet antler grass likes the warm and humid climate in the south of the Yangtze River. Grape stems grow in fertile and well-drained soil and are suitable for forming lawns.

Bison flowers are drought-loving, cold-resistant and trampling-resistant in all parts of the country. Grape stems are developed and should form lawns.

Leymus chinensis in North China, Northwest China and Northeast China is cold-resistant, shade-resistant and trampling-resistant. The requirements for soil are not strict, and the green period is long, which is suitable for lawn formation.

Ziwei likes the warmth in the north and south, and calcareous soil with certain cold resistance is the most resistant to pollution.

Rattan and other plants Table 7

The influence of the height (m) of the growing environment in the growing area on environmental pollution.

Temperature, humidity, sunny soil

In the south of North China, roses like light and cold, and the requirements for soil pollution resistance are not strict. Most of the flowers with weak sulfur dioxide resistance are vertical greening.

Wisteria enjoys sunshine all over the country and has strong adaptability to the climate. The fertile soil with good drainage has certain anti-pollution flowers, which can be used for vertical greening.

Ivy enjoys a warm and humid climate in the south, southwest and northwest of China, and has strong adaptability to soil and pollution resistance in all seasons. Changchun is planted vertically.

Honeysuckle (Lonicera. ) Enjoy the sunshine in North China, East China, South China, Northwest China and Southwest China. Shade tolerance and cold tolerance, strong adaptability to soil, long flowering period, fast growth and vertical greening.

Lingxiao is located in the south of North China, with warm and humid climate and strong adaptability to soil. Pollution-resistant flowers are orange-red.

Parthenocissus tricuspidata is resistant to shade and cold, and has strong adaptability to climate. It is an anti-pollution vertical greening material with low requirements on soil and can be used to beautify the sound barrier.