This paper investigates the collapse of masonry buttresses under concentrated lateral loads. A fracture forms at the collapse state, significantly decreasing the resistance to overturning. Conventional analysis assumes that a masonry buttress acts monolithically to resist lateral loads. The current paper demonstrates that this approach is clearly unsafe, and the possibility of a fracture at the collapse state must be considered in the design and assessment of masonry buttresses. By treating the masonry as a continuum, infinitely strong in compression, with no resistance to tension and no possibility for sliding, the writers demonstrate the form of the fracture and determine the critical failure load for typical buttress forms. This approach follows in the tradition of limit analysis of masonry structures as developed by Hey man. General methods are proposed for the overturning analysis of masonry buttresses, and calculation examples are provided. Finally, methods for evaluating the safety of existing buttresses are presented and discussed.

The focus of this research is the real-time assessment of rock strength (unconfined compressive strength, qu) during drilled shaft installations in Florida limestone, where measures of rock strength are provided through five monitored drilling parameters: torque, crowd, rotational speed, penetration rate, and bit diameter. To complete the study, both a laboratory and field investigation were required. This paper covers drill rig instrumentation, measuring rock strength during field drilling, and the comparative analysis of rock strength with conventional methods. Real-time measurements were recorded for each drilling parameter and graphically displayed on an in-cab monitor and wirelessly transmitted to an external computer. Measures of rock strength were estimated using a laboratory-developed equation with the monitored drilling parameters for real-time field assessment. Measuring while drilling in the field took place at three separate locations where drilled shaft load testing occurred. Comparative analyses between the monitored shaft installations and core samples subjected to unconfined compression indicated the results aligned well when recoveries were good. As recoveries diminished, the mean strengths were comparable, but more variable.

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This paper focuses on how to fulfill the objectivity and reliability goals, as well as the efficiency of the e-learning evaluation tools, and their integration in a blended evaluation system. In order to contribute to these goals, a new branch of statistics, i.e. "Statistical Learning", has been chosen to support this study. The proposed techniques can be very simply implemented with little knowledge of arithmetic and with the help of a standard spreadsheet. These techniques can allow us to get the whole picture of the evaluation procedure output, in order to systematically sort the main categories of the different students, and to easily identify the outliers for further assessment.

Florida limestone can be challenging to recover during coring operations, as the rock generally is soft, porous, and often highly weathered. Low recoveries coupled with poor rock quality are common in Florida, which limits the data available for geotechnical design. However, the low recoveries and poor rock quality may be attributable to coring techniques and not the rock’s in situ condition. This paper explores integrating measuring while drilling (MWD) into standard coring procedures to provide in situ strength assessment and optimize core recoveries and rock quality to improve rock mass characterization. Six drilling parameters were monitored during the research, and a controlled drilling environment was developed to investigate each monitored parameter’s effects. Variable drill bit configurations were also explored to investigate the effects of bit geometry. Interdependent relationships between the drilling parameters were discovered and a new concept of operating within optimal drilling parameter ranges based on these relationships is introduced. The coring practices developed in the controlled environment were then tested in natural Florida limestone. It was concluded that operating within the optimal ranges allows in situ strength assessment and improves core recoveries and rock quality.