生态边坡的水力和力学特性分析:试验研究

发布时间：2018-09-06 08:35

【摘要】：植物护坡是一种新型的护坡方式,是很多边坡防治灾害的首选方案。然而在降雨过程中植物的根系可能会诱发沿根系的优势流,使得坡体内孔隙水压力升高,从而降低土体的抗剪强度。另一方面,植物的根系在土中相互缠绕,可增强浅层土体的抗剪强度。在植物护坡过程中到底哪种效应占主导地位目前尚无定论。通过现场试验联合室内三轴试验综合评价植物土体的水力特性和力学特性。首先在室外建立香根草覆盖区、狗牙根草覆盖区和无植被裸土区,在经历一年半自然状态下的干湿循环之后监测3种覆盖区的体积含水率和基质吸力,并计算3个区域的非饱和渗透系数。其次研制取样器并对现场区域的3种土体进行取样,利用现场土样进行三轴剪切试验,研究室外裸土、含狗牙根草土体和含香根草土体的应力应变关系和抗剪强度指标。同时为了与上述经历干湿循环的土体进行对比,也测量了重塑土的渗透系数和抗剪强度。结果为生态边坡的稳定性研究提供了必要的数据和基础。
[Abstract]:Plant slope protection is a new type of slope protection, and it is the first choice for many slopes to prevent and cure disasters. However, during rainfall, plant roots may induce dominant flow along the root system and increase the pore water pressure in the slope, thus reducing the shear strength of the soil. On the other hand, the shearing strength of shallow soil can be enhanced by the twining of plant roots in soil. Which effect is dominant in the process of plant slope protection has not yet been decided. The hydraulic and mechanical properties of plant soil were evaluated by field test and triaxial test. First of all, Vetivergrass cover area, Doggegrass cover area and non-vegetated bare soil area were established. After a year and a half of natural dry and wet cycle, the volume moisture content and matrix suction of the three cover areas were monitored. The unsaturated permeability coefficients of three regions were calculated. Secondly, a sampler was developed and three kinds of soil were sampled in the field area. The stress strain relationship and shear strength index of outdoor bare soil, soil containing Herba canadensis and soil containing Vetiver were studied by triaxial shear test of field soil samples. At the same time, the permeability coefficient and shear strength of the remolded soil were also measured in order to compare with the above soil. The results provide the necessary data and foundation for the study of ecological slope stability.
【作者单位】：哈尔滨工业大学深圳研究生院;深圳市建设综合勘察设计院有限公司;
【基金】：国家自然科学基金项目(51379053) 深圳市科技计划项目(CXZZ20151117174345411)
【分类号】：TU41

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