不同荷载水平及速率下超软土水相核磁共振试验研究

发布时间：2018-01-12 06:06

本文关键词：不同荷载水平及速率下超软土水相核磁共振试验研究　出处：《物理学报》2014年01期 　论文类型：期刊论文

【摘要】：大规模建设中面临越来越多的淤泥等超软土地基处理,其目的是尽可能排出超软土体中的水而使土体固结,以改善其物理力学性能.静动力排水固结法试图利用高能量冲击而将超软土中部分结合水转换为自由水,进而实现更多水的排出而有效固结.然而,目前还不十分清楚能造成这种水相变化的冲击荷载究竟要达到何种水平及速率.为此,在模拟条件的、淤泥土的不同类型荷载水平及速率试验基础上,进行核磁共振水相测试,探索了典型荷载水平及速率下这种超软土中结合水可转化为自由水的条件及规律,主要为:1)对应于通常工程荷载的较低能量真三轴试验荷载速率与水平(1.6 MPa/s与100 kPa及以下),淤泥类超软土中非自由水不能转化为自由水.2)对应于静动力排水固结法条件的高速冲击荷载下(每击荷载水平3787 kPa,速率631.2 MPa/s),非自由水可转化为自由水;且冲击总能量越大(遍数及击数越多),就越易析出自由水.3)约束样品的侧限刚度对非自由水转化为自由水的影响可忽略.
[Abstract]:In the large-scale construction, more and more ultra-soft soil foundation treatment, such as silt, its purpose is to discharge water from the ultra-soft soil as much as possible to make the soil consolidation. In order to improve its physical and mechanical properties, the static and dynamic drainage consolidation method attempts to use high energy impact to convert some combined water in ultra-soft soil into free water, and then realizes the discharge of more water and effective consolidation. At present, it is not very clear what level and rate of impact load can cause this kind of water phase change. Therefore, on the basis of simulating condition, different types of load level and rate of silt soil are tested. Nuclear magnetic resonance (NMR) water phase measurements were carried out to explore the conditions and rules that the combined water in the super soft soil could be converted into free water under typical load levels and rates. It is mainly 1: 1) the lower energy true triaxial test load rate and horizontal load rate corresponding to the normal engineering load are 1. 6 MPa/s and 100 kPa and below). The non-free water can not be transformed into free water. 2) it corresponds to the high speed impact load of static and dynamic drainage consolidation method (3 787 kPa per stroke load level). The rate is 631.2 MPA / s, and the non-free water can be transformed into free water. The larger the total impact energy (the more the number of times and hits, the easier it is to precipitate free water. 3) the effect of the lateral stiffness on the conversion of non-free water to free water can be neglected.
【作者单位】：广东工业大学岩土工程研究所;上海纽迈电子科技有限公司;
【基金】：国家自然科学基金(批准号:51178122)资助的课题~~
【分类号】：TU411
【正文快照】： 1引言近些年来,核磁共振(nuclear magnetic reso-nance,NMR)作为一个跨学科的测试技术方法用于研究不同砂岩岩石、催化剂、胶体和生物组织[1],并且越来越多地应用于包括岩土介质在内的各种材料物理及几何特征测试及估算,如用于水泥在水渐进析出变化状态下各类凝胶孔隙水特征[2

【相似文献】