Design methodology for drilled-shafts-stabilized slope.

摘要

Drilled shafts have been frequently used as an effective remedial measure to stabilize a slope or embankment. However, problems still exist due to difficulties involved in the accurate determination of p-y (load-deflection) curves and the lateral force distribution on a drilled shaft. The major research objectives of this dissertation are: (a) evaluation of three specific methods for determining the site specific p-y curves; (b) development of a design methodology for the analysis and design of drilled shafts in stabilizing a slope.; Lateral load tests have been performed at four project sites. Based on the test results obtained, comprehensive evaluations of three methods for determining the p-y curves have been performed and documented.; Due to the indeterminate nature of the limit equilibrium analysis method of slices, a hypothesis is presented, which states that the transferring of the interslice force within the soil mass follows the principle of the least resistance. Based on this hypothesis, an equation was obtained for the determination of inclination angles of interslice forces. Furthermore, a method for directly determining the interslice forces was derived.; A design methodology for drilled shaft stabilized slope system has been developed successfully. Notable innovations include: (a) the algorithm for the determination of the interslice force in the method of slices analysis, (b) the adoption of the knowledge gained from the arching mechanism in calculating the load transferred from the soil mass to the drilled shaft, (c) the development of a method for determining the global factor of safety for the slope reinforced with the drilled shafts.; The main conclusions of this research work are as follows. First, the procedure of using the inclinometer data from the lateral load tests is an alternative to determine site specific p-y curves. Secondly, the methodology for directly determining the interslice force in the method of slice limit equilibrium slope stability analysis appears to perform very well. Finally, the system design methodology for drilled shafts stabilized slopes has been developed and implemented into a PC program. The two engineering cases have provided necessary verifications of the validity of the proposed method.