The Protecting Techniques Of Slope And Roadbed Along The Desert Expressway Between Yulin And Jingbian

With the rapid development of expressway construction in China, the higher need for ecological environment and landscape rebuild is put forward, and receives prevalent attention from some related departments. The highway about 116 km between Yulin and Jingbian is the first desert expressway in China, thereinto, the road of wind and sand roadbed is 80 km, and about 69% in total length; the area of various sand land along the highway is about 85% in total management area. So the high degree of virescence along the expressway plays a very important role in safety of protecting road.Via investigation on the spot, refering to some research achievements and discussion about slope protecting technologys at the sides of highway, the paper analyzes the effects of wind and sand activities to expressway and the quality evaluation of virescence land. Aimming at particularity of desert highway, it mainly investigates and analyzes the slope protecting techniques at the sides of highway, the selection and configuration of virescence vegetation, virescence construction technologys, and so on. Finally, it educes following important conclusions:1,The protecting technique of straw reseau adding vegetation is one of optimal, economical, practical protecting measures, this measure can be largely extended to the same regions; enwrapping slope with yellow soil is feasible in near yellow siol regions; the slope protecting method of level bench planting is perfect on the yellow siol slope; the slope protecting technique of three-dimensional vegetation network is costly, it can be used in the condition that there is difficulty in constructing blocking sand obstruction; liquid insufflation protecting slope is also costly, can be utilized on the steep slope or the slope manual planting can't operate.2,Accoding to experimental effects and integrated analyzing evaluation, this paper presents following typical protecting modes:⑴Straw reseau covering slope and Amorpha fruticosa Linn, Caragana intermedia Huet Keng, Mongolia You planting in zonal and mix. Average two rows is one strip, space between strips is 1 m, row spacing between individuals is 0.5×0.5, one row Huoju trees in slope angle, plant spacing is 3 m. ⑵Straw reseau covering slope and Hedysarum mongolicum Turcz, Amorpha fruticosa Linn planting in zonal and mix. Average two rows is one strip, space between strips is 1 m, row spacing between individuals is 0.5×0.5, one row Prunus pedunculata in slope angle, plant spacing is 1 m.⑶Straw reseau covering slope, planting Amorpha fruticosa Linn or Caragana intermedia Huet Keng on the upslope and sandland cypress on the downslope. Row spacing between individuals is 0.5×1.0, one row sandland osier in slope angle, plant spacing is 1 m.⑷Straw reseau covering slope, planting Caragana intermedia Huet Keng on the upslope, planting Amorpha fruticosa Linn on the middle-slope and planting Hippophae rhamnoides Linn on the downslope. Row spacing between individuals is 0.5×0.5.3,The protecting modes on the two sides of the road. Froming synthetical analysis and evaluation of investigation situation about ten species vegetation growth status and protecting and beautifying function, the paper recommends following typical modes of protecting roadbed slope of desert expressway:⑴Outward roadbeb, there are two rows of Amorpha fruticosa Linn, two rows of Pinus sylvestris L.var.mongolica Litv, two rows of Populus albavar pyramidalid Bunge in turn, and seeding Shadawang in space.⑵Two rows of Caragana intermedia Huet Keng, three rows of Pinus sylvestris L.var.mongolica Litv and Populus albavar pyramidalid Bunge in mix, and seeding Mebecagosatira in space.⑶Two rows of Shadibai, two rows of Shaliu, and three rows of Pinus sylvestris L.var.mongolica Litv and Populus opera Hs, seeding Shadawang in space.⑷Two rows of Amorpha fruticosa Linn, three rows of Hippophae rhamnoides Linn, and three rows of Populus opera Hs.From these four configuration scheme, we can see the vegetation arrangement is from low to high, and from shrub to evergreen silvae, and to high silvae, the plane level increases outwardly, these abibe by the design principle"low near roadbed, high far roadbed". This kind of vegetation configuration can make people see all plants scenery. Shrub can not only receive more sunlight and grows qucikly, but also has efficient function of fixing sand and stopping wind, because its planting density is very heavy...