Master of Science, The Ohio State University, 2009, Civil Engineering

As part of the Ohio Department of Transportation's (ODOT's) ongoing effort to solve engineering problems for the Ohio transportation system through research, The Ohio State University has undertaken a study entitled “Bioengineering for Land Stabilization” under the direction of Professor Patrick J. Fox and Professor Emeritus T. H. Wu. A large number of slopes and embankments throughout Ohio are experiencing shallow slope failures and/or erosion problems. The aim of this study is to identify bioengineering methods to address ODOT's slope stabilization needs in response to these occurrences. Bioengineering is an ecologically, and often economically, attractive alternative to conventional slope stabilization techniques. The objectives of this research are: 1) to identify important factors that control success or failure of bioengineering methods, 2) to develop installation techniques and designs for successful application of bioengineering methods, and 3) to provide thorough documentation to aid in the development of future design guides for bioengineering work for ODOT. Three field installations were conducted and monitored at demonstration sites located in Muskingum, Logan and Union Counties. Results indicate that biostabilization methods can be effective for the stabilization of shallow (less than 3 – 4 ft.) slides if vegetation can be established. Establishment of vegetation is dependent on local soil and climate conditions, especially during the first growing season after installation. The use of instrumentation (tensiometers, piezometers) can be effective in predicting vegetation survivability. Side-by-side panel comparisons indicated that varying installation techniques do not affect the survivability of live willow poles. The cost of bioengineering stabilization is expected to be approximately 25% less than that of conventional methods.

Committee: Patrick Fox (Advisor); Tien Wu (Committee Member); Halil Sezen (Committee Member) Subjects: Civil Engineering; Engineering

Master of Science, The Ohio State University, 2009, Civil Engineering

As part of the Ohio Department of Transportation's (ODOT's) ongoing effort to solve engineering problems for the Ohio transportation system through research, The Ohio State University has undertaken a Bio-Engineering for Land Stabilization study under the direction of Professor Patrick J. Fox and Professor Emeritus T. H. Wu. Bioengineering is the use of vegetation for slope stabilization and has been used with success throughout the world; however, not much work on this topic has been performed in the mid-western United States. The aim of this study is to identify bioengineering methods to address ODOT's land stabilization needs in response to the all too common occurrence of shallow landslides. Bioengineering methods offer environmentally and economically attractive alternatives to traditional approaches to remediate and prevent such landslides. This research plans to achieve several objectives through the construction of three field demonstration projects: (1) to identify important factors that control success or failure of bioengineering methods, (2) to develop installation techniques and designs for successful application of bioengineering methods, (3) to provide thorough documentation to guide future work in bioengineering for ODOT, and (4) to develop new monitoring and testing methods that may be required for bioengineering projects. To date, research demonstration sites have been selected in Muskingum, Logan, and Union Counties and design and construction efforts are underway. Initial results of the project indicate that bioengineering installations, such as live willow poles, can be effective for the stabilization of shallow slides if the vegetation can be established.

Committee: Patrick Fox PhD (Advisor); Tien Wu PhD (Committee Co-Chair); William Wolfe PhD (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, University of Akron, 2010, Civil Engineering

A practical methodology for stability analysis and design of drilled shafts reinforced slopes was developed utilizing limiting equilibrium method of slices. Complex soil stratifications and general failure slip surfaces can be handled in the developed method. The effect of soil arching due to the presence of the drilled shafts was accounted for by using a load transfer factor. The numerical values of the load transfer factor were developed based on 3-D FEM parametric study results. Many of the design variables controlling the slope/shaft systems, such: drilled shafts size, shafts location, and the required spacing between the drilled shafts can be successfully determined from the developed method. The optimum location can be searched for and determined from the developed methodology. The global factor of safety for slope/shaft systems and the forces acting on the stabilizing drilled shafts due to the moving ground can be successfully estimated. For the purpose of verifying the validity of the proposed design methodology, the results of a field load testing program on the fully instrumented drilled shafts installed on an existing failed slope together with the companion 3-D FEM simulations are presented. This real case was analyzed using the proposed analysis and design methodology, the analysis results were compared with the FEM results, and it is found that they are in good agreement. In addition, Real-time instrumentation and monitoring were carried out for three landslide sites in the Southern part of Ohio. Various types of instruments were extensively installed inside the stabilizing shafts and the surrounding soils to monitor and better understand the behavior of slope/shaft systems. The field instrumentation and monitoring processes have provided excellent and unique information on the lateral responses of shafts undergoing slope movements. Also, the results of the instrumented cases have provided that the structural design (moments, shear, lateral deflection (open full item for complete abstract)

Committee: Robert Liang Dr. (Advisor); Dr. Craig Menzemer PhD (Committee Member); Dr. Ala Abbas PhD (Committee Member); Dr. Zhenhai Xia PhD (Committee Member); Dr. Kevin Kreider PhD (Committee Member) Subjects: Civil Engineering