HDPE蜂巢式固沙障研制与防沙效应实验研究

 采用先进的HDPE新材料制成蜂巢式固沙障来替代传统的草方格。研究发现:HDPE蜂巢式固沙障可以增大下垫面的粗糙度,明显降低了地表底层风速,进而减弱输沙强度,使流沙表面得以稳定。在格状沙障内,由于气流的涡旋作用,使原始沙面充分蚀积,最后达到平衡状态,形成稳定的凹曲面。下凹的深度(h)与凹面玄长(S)的比值为13.6/100~13.2/100,这种下凹的深度(h)与凹面玄长(S)的比值与传统有效的草方格（草方格为13.3/100）防沙效应相当,其二者流场特性也相同。这种稳定的凹曲面,对不饱和风沙流具一种升力效应,形成沙物质的非堆积搬运条件,这是格状沙障作用的关键。实验表明,选用孔隙度为40％、高20 cm的HDPE固沙障防沙效果显著。

Experimental Study on Sand-binding Effect of HDPE Comb-liked Sand Barriers

New kind of comb-liked sand barrier, composed of the HDPE material, was used to substitute the traditional straw checkerboard sand barrier for experiment. Some conclusions were draw as follows: HDPE comb-liked sand barriers can increase the roughness of earth surface, decrease the lower wind speed, weaken sand transport, and then make moving sand surface stable. Due to the eddy role of air flow, the original sand surface within checkerboard sand barriers is in an equilibrium state after experiencing wind erosion and sand accumulation completely, and under this condition, a stable concave surface on sand surface may be formed. The ratio of the lowest erosion depth (h) to chord of concave surface ranges from 13.6/100 to 13.2/100, and is near to the value of traditional straw checkerboard sand barriers (13.3/100). The both have similar characteristic of airflow field. This stable concave surface produces a lifting effect for unsaturated wind-blown sand, which forms the un-deposed and carried condition of sand materials. The experiment showed that 20 cm high HDPE sand barriers with the 40% porosity will get obvious sand-defended effect.