Centrifuge Modelling of Compaction Grouting

9622399压实灌浆是在高压下将坚硬的水泥基灌浆注浆入土中。现有和明确的证据表明，该技术是一种阻止或逆转地面沉降影响的方法，并能改变和改善现有土壤的特性和地应力条件。应用程序绝大多数掌握在专业顾问和承包商手中，但即使在他们中间，关于土壤和灌浆力学细节的问题仍然存在。该项目将回答注浆深度、注浆压力、注浆配合比、土体条件和地应力之间的相互关系以及由此对土体压实、剪切变形和土体位移的影响。初步的离心机表明，这种小的1-g模型的测试技术可以展示一般的行为机制。然而，为了建立全面的现场响应的可靠表示，应力校正离心机模型是必要的。这项工作承诺与北卡罗来纳州立大学正在进行的由NSF赞助的注浆有限元建模和全尺寸现场测试研究以及与美国陆军陆战队水道实验站的合作互动。完成该奖项的离心机模型将在解决与注浆和注浆方案设计相关的问题上大有裨益，包括可变参数，如注浆深度、压力、注浆角度和表面附加量。灌浆承包商也承诺就这一项目提供建议，并计划对研究人员团队进行实际培训。***

9622399 Compaction grouting is the injection under high pressure of stiff cement-based grout into soil. There is existing and clear evidence that the technique works as a method to halt or reverse the effects of ground settlement, and to modify and improve characteristics of existing soils and in situ stress conditions. The application is overwhelmingly in the hands of specialized consultants and contractors, but even among them, questions persist about the details of soil and grout mechanics. This project will answer questions on the interrelationship between injection depth, grout pressure, grout mix, soil conditions and in situ stress, and the resulting effects on soil compaction, shear deformation, and soil displacement. Preliminary centrifuge indicates that this test technique with small, 1-g models can demonstrate general mechanisms of behavior. However, stress-correct centrifuge models are necessary to develop reliable representation of full-scale field response. There is a commitment in this work for cooperative interaction with on- going NSF-sponsored research on FEM modeling and full-scale field testing of grout injection at North Carolina State University, and with the U.S. Army Corps' Waterways Experiment Station. The centrifuge models completed for this award will be highly complimentary to address questions relating to the design of grout and injection schemes, including variable parameters such as injection depth, pressure, grout injection angle, and surface surcharge. Commitment has also been made by grouting contractors to advise on this project, and plans are included for practical training of researcher teams. ***