饱和土中劈裂灌浆压力研究  

Study on grouting pressure of fracture grouting in saturated soil

作　　者：邹金峰[1] 徐望国[1] 罗强[1] 李亮[1] 杨小礼[1] 

机构地区：[1]中南大学土木建筑学院,长沙410075

出　　处：《岩土力学》2008年第7期1802-1806,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No50408020)资助

摘　　要：在塑性力学和大变形理论的基础上,分析土体在劈裂灌浆初始阶段的力学机理。将劈裂灌浆的初始阶段视为无限土体中的圆孔扩张问题,并将圆孔周围土体中的应力分布分为两个区域。在弹性区中土体服从小变形假设,在塑性区中服从大变形假设。利用水力压裂理论和圆孔扩张理论,假设孔隙水压力大于或等于初始应力与扩张应力增量之和时,土体将出现拉应力,若拉应力超过土的抗拉强度,土体将产生开裂,此时的灌浆压力就为初始劈裂灌浆压力。当土体在灌浆压力作用下,大小主应力正好换位时,则出现劈裂时的灌浆压力就为二次劈裂灌浆压力值,推导出饱和土体劈裂灌浆压力的理论公式。该理论的计算结果与工程实测结果比较接近,初步证实了该理论的可靠性。Bases on theory of plasticity and the large strain, the early phase of fracture grouting is regarded as the question of cavity expansion in infinite soil. The stress distribution due to the cavity expansion in soil is considered as two zones. The deformation following little deformation in elastic zone and large-deformation in plastic zone is taken into consideration. By using the theory of cavity expansion, hydro-fracture and pore water pressure theory, on the assumption that the sum of initialization stress of soil and increment due to cavity expansion is equal to the pull strength of soil, the soil is fractured by grouting. If the large and small stress of soil is conversion, the second fracture grouting takes place. Based on the above theory, the fracture grouting pressure in saturated soil is given. According to the comparison, the result of the present theory is very near to the those of the engineering practice.

关 键 词：灌浆压力 劈裂灌浆 饱和土体 水力劈裂 孔隙水压力 

分 类 号：TU435[建筑科学—岩土工程]