Nittany Lions' New Convocation Center: Rock Solid with LMG

Limited Mobility Grouting (LMG) has been a relatively recent technology that began in the United States. Applications of this method of ground improvement are still evolving. The Bryce Jordan Center, Penn State University, State College, PA, is an example of the use of LMG in karst for rock supported spread footings. Although a deviation from the traditional compaction grout roots of LMG, the application provided assurance that the foundation rock was consistent/continuous. This paper provides a brief discussion of the exploration methods used to assess the site variability, and the development of the foundation design. This approach was developed as a cost saving alternative to drilled shafts, and represents the first recent structure where the State owner of this facility had allowed foundations other than drilled piers for buildings in karst. The paper includes discussion of the design methodology and estimating procedures, as well as construction experience. Conclusions related to the construction activities, difficulties, and results are included. The design methodology builds on the work of Schmertmann and Henry to develop a strength-based approach to unifying the rock mass to limit settlements under foundation loadings. The success of the method has been demonstrated by six years of satisfactory performance. As a unique application of LMG to rock foundations, particularly on a structure of this magnitude with column loads up to 2500 kips (11,000 kN), this case study serves as an example of successful innovation with an evolving technology.