A field study of the behavior of small-scale single rammed aggregate piers, testing methodology and interpretation

AbstractThis paper presents the measured behavior of small-scale single rammed aggregate piers as a function of the piers’ slenderness ratio. For this purpose, loading tests at the site were carried out on two groups of single rammed aggregate piers with a constant diameter of 135 mm and variable lengths of 350–1000 mm, and two groups with a constant length of 1000 mm and various diameters of 105–185 mm. The testing area consisted of relatively uniform saturated soft alluvial clay overlain by a 1-m-thick wet soft-to-stiff silt layer. Results show that when length and diameter change, the pier load and top settlement variations at the design limit, in terms of the slenderness ratio, are not in the same direction while other design limit parameters’ variations are. The variations of design limit parameters in the two modes of change to pier length and diameter including the applied load, top settlement, stiffness modulus and pier modulus, in terms of the slenderness ratio, make a linear function while the variations of load and settlement ratio show an exponential function. Interpretations of the test results are particularly focused on the load-settlement behavior and variations of design limit parameters as a function of pier slenderness ratios

Centrifuge model studies on anchored geosynthetic slopes for coastal shore protection

This paper evaluates performance of anchored geosynthetic systems (AGS) on stability of slopes under seepage condition using a centrifuge modeling technique. A series of centrifuge tests were carried out at 50 g on unreinforced and AGS slope models, using a centrifuge container equipped with seepage flow simulator. AGS slope models were tested by varying slope inclination, number of anchors and keeping inclination of anchors as constant. The water was allowed to seep through the model slopes during flight at 50g. Ground anchors were modeled as drilled pre-tensioned anchors using sand epoxy mixture, polyester strand and a plastic tube. An anchor inclination of 15 degrees with the horizontal was adopted for AGS slopes. A layer of geocomposite was used for modeling geosynthetic component of anchored geosynthetic systems. All models were instrumented to measure surface settlements and pore water pressure within the slope at onset of seepage during centrifuge test. A digital image analysis technique was adopted to trace displacement vectors of plastic markers embedded toward the front elevation of the model and plastic markers glued to facing during model construction. Analysis and interpretation of centrifuge model test results indicate that the stability and deformation behavior of slopes, under seepage conditions, can be substantially improved using anchored geosynthetic systems. With an increase in slope inclination and reduction in number of anchors, surface settlements and face movements were observed to increase substantially. Further, stability analysis results on the unreinforced and AGS slope models were found to be in good agreement with those of physically observed centrifuge test results. (C) 2012 Elsevier Ltd. All rights reserved

Centrifuge study of anchored geosynthetic slopes

This paper presents the results of centrifuge model testing on slopes reinforced by anchored geosynthetics and subjected to seepage conditions. The tests were conducted on 2V:1H slope models under steady seepage condition at 50g. Surface settlements and pore water pressures at different locations were recorded during the test. The influence of anchor stiffness, anchor length, and anchor pretensioning were examined. With an increase in anchor strength or stiffness, a considerable decrease in crest settlements and face movements was observed. Further, pretensioning of strands was found to be effective in enhancing the efficiency of anchored geosynthetic systems. Limit equilibrium stability analyses were in good agreement with the experimental results of slope models at failure

Integrating association rules mined from health-care data with ontological information for automated knowledge generation

Association rule mining can be combined with complex network theory to automatically create a knowledge base that reveals how certain drugs cause side-effects on patients when they interact with other drugs taken by the patient when they have two or more diseases. The drugs will interact with on-target and off-target proteins often in an unpredictable way. A computational approach is necessary to be able to unravel the complex relationships between disease comorbidities. We built statistical models from the publicly available FAERS dataset to reveal interesting and potentially harmful drug combinations based on sideeffects and relationships between co-morbid diseases. This information is very useful to medical practitioners to tailor patient prescriptions for optimal therapy