Elucidation of improvement mechanism and evaluation of improvement effect on ground improved by compaction grouting

压实灌浆改良地基改良机理阐明及改良效果评价

基本信息

批准号：
12450193
负责人：
MATSUI Tamotsu
金额：
$ 7.23万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

In this study, the performance of compaction grouting has been investigated through laboratory and field experimental works. For the laboratory experimental work, large-scale calibration chamber was developed. In this chamber, sandy samples (1.40 m in diameter and 1.45 m high) are prepared, consolidated and injected (using grout mortar) under conditions highly simulating the actual field conditions As the results, it was confirmed its accurate basic performance. As for the field tests, analytical study was involved based on the results of three field tests conducted in Nagoya, in Osaka and under the old taxiway of Tokyo International Airport.The main findings of this study are as follows : (1) The performance in terms of ground surface upheave is dependent on the injection depth. (2) The critical depth that characterizes the shallow and deep injections is dependent on the compaction grout pile diameter. (3) The relatively shallow injections are governed by the condition of conical shea … More ring failure of the soils overlying the masses being injected. At conical shearing failure, the attained injection pressure and grout volume are dependent on the overburden pressure and shear strength characteristics. (4) The treatment effectiveness of relatively shallow injections may be improved by terminating the injection process at just before the onset of ground surface upheave. (5) In planning the grouting works for the applications for lifting of settled structures and foundations, the required lifts can be provided only by the injections shallower than the critical depth. (6) For the applications such as in liquefaction prevention works, smaller-diameter piles may be injected while going shallower. (7) For relatively deep injections, the vertical overburden pressure has no appreciable effect on the performance. However, the performance is highly influenced by the local soil compressibility. If deformation by relative displacement of the soil particles is the dominant mechanism, the attained injection pressure will be highly correlated to the local fines content. If deformation by particle crushing is the dominant mechanism, the resulting crushing depends on mainly injection pressure. (8) The maximum pressure from injecting a given grout volume correlates well with the tip resistance of CPT test. This correlation qualifies the maximum injection pressure as reliable criteria for evaluating the performance of compaction grouting operations. (9) In the loose sand, the improved area is limited around the grouted area. However, the wide area is uniformly improved in the dense sand. Less

在这项研究中，已经通过实验室和现场实验工作研究了压实灌浆的性能。对于实验室实验工作，开发了大规模校准室。在此腔室中，在高度模拟实际田间条件的条件下制备了沙质样品（直径为1.40 m）（直径1.40 m）（高1.45 m高），并注入（使用灌浆砂浆），因为结果确认了其准确的基本性能。至于现场测试，基于在南哥亚，大阪和东京国际机场的旧出租车下进行的三项现场测试的结果涉及分析研究。这项研究的主要发现如下：（1）地面上的地面上的性能取决于注射深度。（2）表征浅和深度注射的临界深度取决于压实灌浆桩直径。（3）相对浅的注射受圆锥形乳木果的状态控制……覆盖着注射质量的土壤的更多环失败。在圆锥形剪切失败时，已达到的注入压力和灌浆量取决于覆盖压力和剪切强度特性。（4）可以通过在地面膨胀开始之前终止注射过程来提高相对浅注射的治疗效果。（5）在规划灌浆工作的工作中，用于提升定居结构和基础的应用程序，只有与临界深度较浅的注射只能提供所需的升降机。（6）对于诸如预防液体摘要工程的应用，可以在较浅时注射较小的直径钢琴。（7）对于相对较深的注射，垂直覆盖压力对性能没有明显的影响。但是，该性能受到当地土壤累积性的高度影响。如果土壤颗粒相对位移的变形是主要机制，则所达到的注射压力将与局部罚款含量高度相关。如果颗粒粉碎的变形是主要机制，则所产生的压碎取决于注射压力。（8）注入给定的灌浆体积的最大压力与CPT测试的尖端电阻良好相关。这种相关性将最大注入压力作为评估压实灌浆操作的性能的可靠标准。（9）在宽松的沙子中，改进的区域在成年区域周围受到限制。但是，在密集的沙子中，宽面积均匀改善。较少的