Currently, cement base grout is used widely for sealing of the rock fractures in order to decrease the permeability of rock mass. Grouting procedure is one of the main tasks in cycle of rock excavation. In addition, huge amount of grout should be used during dam construction in order to seal the bedding and embankment walls. Therefore, considering the effect of grouting in duration and cost of the project, improving the design methods seems essential. In successful grouting the goal is to achieve the required sealing of fractures while avoiding ground movement due to applied pressure. Empirical methods have been developed to decide the pumping pressure, grout mix properties and stop criteria in order to fulfill requirements of successful grouting but there are ambiguities in using them and performance of them have been questioned. In these methods, assumptions and criteria are based on rules of thumbs and experiences from previous projects. The main uncertainties connected to these methods are identifying amount of grout spread and state of the fracture. Theoretical approach is an analytical solution which provides the chance for estimation of penetration length of the grout in real time. Furthermore, void filling fracture aperture and trend of the grout flow are estimated. As the development of this theory, elastic and ultimate jacking limits have been established based on the estimated penetration length. Therefore, it is possible to identify jacking of the fracture and estimate the state of the fracture in real time.  In this research work, performance of this theoretical approach which is called “Real Time Grouting Control Method” has been validated through case studies. Properties of the used material, data for pressure and flow in addition to geological characteristics have been gathered from projects in sedimentary rock (Gotvand Dam in Iran and THX Dam in Laos) and hard rock (City Line Project in Sweden). This theory made it possible to observe overflow of grout and jacking of the fractures in sedimentary rock. In place of hard rock with mostly vertical fractures, this theoretical approach confirms usage of higher pressure which will shorten the grouting time. In this research work, variation in properties of the grout mix during grouting has been neglected. moreover, orientation of the fracture and its deformation due to injection pressure are not considered. Despite these assumptions, the results were promising and performance this approach in estimation of grout spread and identifying jacking of the fracture has been verified. / <p>QC 20130520</p> / Rafi, J, Stille, H, Bagheri, M, 2012. Applying “Real Time Grouting Control Method” in Sedimentary Rock, in 4th International Conference on Grouting and Deep Mixing. 16-18 February, New Orleans-USA. / Rafi J, Stille H, 2013. Controlling jacking of rock considering spread of grout and grouting pressure, Accepted in Journal of Tunneling and Underground Space Technology. / Rafi J, Tsuji M, Stille H, 2013. Theoretical Approaches in Grouting Fractures of the Rock Mass: Theories and Applications. Accepted in the 47th US Rock Mechanics / Geomechanics Symposium. 23-26 June, San Francisco, CA, USA. / Rafi J, Tsuji M, Stille H, 2013. Theoretical approaches in grouting design: estimation of penetration length and fracture deformation in real time in Bergmekanikdagen, 11 March, Stockholm-Sweden.

No description available.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1981. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 91-93. / by Lucile Merrill Jones. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1979. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 316-327. / by Michael Fehler. / Ph.D.

Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Vita. / Bibliography : leaves 110-122. / by Michael L. Feves. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography: leaves 164-168. / by Teng-Fong Wong. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography: leaves 378-399. / by David H. Johnston. / Ph.D.

Appalachia requires design guidelines for the increasingly popular multi-seam longwall method. Entry layouts often depart from the ideal when finally developed. The thesis examines the occurrence of ground control problems, and possibilities for improvements in strata control, in a variety of undermining situations. The effects of upper seam loading on undermining operations are invest~gated using physical modelling. Photoelastic stress analysis is used as a powerful research tool to analyze complex multiple seam entry systems. Yield pillar use is also examined, in anticipation of their widespread application for ground control. Case examples support the research findings, and specific conclusions aim to assist layout design in interactive zones. / Master of Science

This experimental investigation was conducted to assess the effect of zero point of charge (ZPC) environment on fracture behavior of rocks. The material parameters selected for this purpose were fracture toughness and specific work of fracture. These properties were determined for three rock types in five environments. Semi-circular bend specimens of dolomitic limestone, Sioux quartzite and Westerly granite were tested in aqueous solutions of aluminum chloride, calcium chloride and polyethylene oxide, all at ZPC conditions. These rocks were also tested in atmospheric air and distilled deionized water. For every rock type, the results obtained for the tests done in each of the ZPC environment were statistically compared with the results in water. This comparison was also made for air and water. The average fracture toughness in each of the ZPC environments, for all three rock types, was found to be less than the corresponding average in water. The specific work of fracture results also indicated reduction in ZPC environments as compared to water. The statistical analysis of the results, however, showed that this reduction was significant in some but not all of the rock-environment combinations tested in this investigation. / Master of Science

Portals are frequently an exceedingly difficult area in terms of ground control due to the near-surface, weathered, and highly discontinuous rock mass conditions. Surface and subsurface failures involving portals were analyzed using over 500 case histories which were organized into a database. Critical factors contributing to both stability and instability were isolated, and failures were classified according to location. Correlations between rock mass classes and types of portal failure were made and a four step stability analysis methodology defined. To determine critical sections of portal approach cuts for stability analysis, the Geomechanics Classification System was appended with discontinuity orientation adjustments. The most common type of failure for active portals, that of 'Crown Face Overbreak' failure, was investigated and modelled for design and support purposes. Results are confirmed using case study data. Excavation and support guidelines, based on database information the predicted failure zone from the 'Crown Face Overbreak' model are provided. / Ph. D.