刷状草方格固沙障机织工艺与防沙效果研究

Study on weaving technology and sand control effect of brush straw checkerboard barriers

草方格固沙障因其固沙效果好、成本低廉且环保的特点,被认为是中国乃至世界各地防沙治沙的最有效方式,亦被称为“中国魔方”.但长期以来,草方格沙障的施工方法未得到改进,依然需要有经验的工人利用铁锨将麦草扎入沙地中,形成半隐蔽式草方格,这一过程耗时耗力,不能满足当前我国防沙治沙事业提质增效的新时代要求.本文研制了一种将麦草通过机械编织而成的刷状草方格固沙障,使草方格沙障施工效率提高60%以上.通过对刷状草方格固沙障防沙效果开展系统的风洞实验和野外观测研究发现:(1)与传统草方格沙障相同,刷状草方格固沙障内部形成了明显的气流减速区和流向涡旋,沙障顶部出现了明显的抬升气流.当风速低于20 m s^(-1)时,固沙障可使地表风速降低80%以上;(2)刷状草方格与传统草方格沙障对风沙流的扰动作用相同,沙障内输沙率随高度变化不再遵循指数递减规律,输沙率随高度增加先增大后减小,在沙障顶部出现最大值;(3)刷状草方格固沙障固沙效率(Rs)随风速的增大线性减小,但在一般沙漠地区Rs可达到90%以上.刷状草方格有望替代传统草方格固沙障,减轻劳动强度,提高施工效率,为草方格沙障的机械化编织和智能化施工提供技术支撑.

Because of its low cost and environmental protection characteristics,the straw checkerboard barrier,revered as the“Chinese Rubik’s Cube,”is globally recognized as a highly effective method for controlling wind-blown sand owing to its cost-effectiveness and eco-friendly nature.However,it does have a downside:its construction process is labor-intensive and inefficient,requiring experienced workers to manually insert wheat straw into the desert,forming a semi-hidden checkerboard sand barrier.Herein,we introduce an innovative solution designed to address these challenges,namely a mechanically woven brush straw checkerboard barrier.This technology,made from wheat straw,has significantly increased the construction efficiency of straw checkerboard barriers by over 60%.Through both wind tunnel experiments and field observations,we examined the effects of this new brush straw checkerboard barrier on the control of wind-blown sand.Our findings were as follows.(1)Similar to the traditional straw checkerboard barrier,the brush straw checkerboard barrier creates a noticeable airflow deceleration zone and flow vortex inside it,along with a prominent lifting airflow at the top of the sand barrier.When the wind speed is less than 20 m s^(−1),the sand barrier can reduce wind speed by over 80%.(2)The brush straw checkerboard barrier’s impact on wind-blown sand flow mirrors that of the traditional straw checkerboard barrier.As height increases,the sand transport rate within the barrier no longer follows an exponential decrease;instead,it initially rises before falling,reaching its peak at the top of the sand barrier.(3)The sand fixation efficiency(Rs)of the brush straw checkerboard barrier decreases linearly as wind speed increases.However,Rs can still achieve more than 90%in desert areas.These findings suggest that brush straw checkerboard barriers could potentially replace traditional straw checkerboard barriers.They not only reduce workers’labor intensity but also improve construction efficiency.Therefore,this technology offers promising prospects for mechanized weaving and intelligent construction of straw checkerboard barriers.