宁夏中卫县沙坡头地区黑色泥质页岩固沙性能研究

The primary study on the property of solidifying sand of the black muddy shale in Shapotou Region, Zhongwei, Ningxia Province

我国西北干旱半干旱地区,生态环境极为脆弱,土地沙漠化问题十分突出。防风固沙,恢复植被,遏制沙漠化,改善生态环境,是我国西部大开发战略和加快西部经济腾飞的主要任务之一。防风治沙首先要解决的问题是固沙保水。文章提出了利用宁夏腾格里沙漠东南缘中卫县沙坡头地区香山北麓的黑色泥质页岩在自然条件下天然胶结成壳作用于固沙的可能性。这类黑色泥质页岩具有遇水则吸水软化,风干则形成薄硬壳之特点。在斜坡坡面上或坡脚风化破碎或构造破碎或人工开挖的黑色泥质页岩碎块堆积的表面常形成1层1～5cm的硬壳。这类黑色泥质页岩在500℃时灼减量高达17 56%,说明具有很高的有机质含量,同时P2O5和K2O含量也较高,有利于成壤和植物生长。黑色泥质页岩的天然胶结成壳作用与地表破碎的黑色泥质页岩堆积和特定的干旱半干旱气候以及本身成分、结构有关。这一硬壳层不但具有一定的强度和抗风蚀能力,而且还具有一定的吸水性和保水性。因此,借鉴草方格固沙方法,就地取材,充分利用黑色泥质页岩在自然条件下的天然胶结成壳性能,用于沙漠治理中的固沙。进一步对黑色泥质页岩天然胶结成壳的机理进行深入研究,并开展黑色泥质页岩固沙试验研究,有可能为腾格里沙漠治理开辟新的途径。

The ecological environment is very fragile in the arid area and desertification of land is one of main barriers to the economic and social development of Northwest China. Windproof and solidifying sand, preventing desertification, and improving ecological environment are the main tasks in carrying out the Project of Development in West China and in speeding up the economic flying step.\;The first task in control of desertification is to solidify sand and preserve moisture. It is proposed in this paper that the natural cementation and shellization of the black muddy shale exposed in the Shapotou region, North slope of Xiangshan Mountain, southeast margin of Tenggeli Desert, could be used to solidify sand. Primary study shows that when the fractured black muddy shale meets rainfall it will absorb water and become soft, and when it is drought under natural condition it will form a hard shell on the surface of fractured black muddy shale pile. Chemical analysis for the black muddy shale indicates that its loss amount is about 17\^56% at 500℃, which shows that it contains a great deal of organic material. In addition, its P\-2O\-5 and K\-2O content is higher, that is beneficial to plant growth and soil formation. The natural cementation and shellization of the black muddy shale is a result of combination of its chemical ingredients and texture features with special arid climate. The shell formed on the surface of black muddy shale has a certain mechanical stength against wind erosion.In addition it has certain capability to absorb and keep miosture.\;It is suggested that the black muddy shale studies above may be a potential soldifying sand material.Taking similar way to grass grid method, utilization of the natural cementation and shellization of the black muddy shale, and making full use of material available in-situ, we could develop a new approach to control desertification. But further study on the mechanism of the natural cementation and shellization of the black muddy shale and in-situ test of solidifying sand with muddy shale are necessary.