doi:10.3850/GI023

ABSTRACT

The work presented in this paper identifies the advantages of using autonomous monitoring at construction sites utilizing ground improvement techniques. The Shape-Acceleration Array (SAA) utilizes Micro-Electro-Mechanical Systems (MEMS) technologies. The SAA is capable of measuring in situ (field) 3D ground deformation every 0.305 meters and 3D soil vibration at 2.4 m intervals up to a depth of one hundred meters. The system accuracy of the SAA is ± 1.5 mm per 30m; an empirically derived specification from a large number of datasets. This sensor array can be installed vertically, in a method similar to that used for traditional inclinometer casing, or horizontally. Each sensor array is connected to a wireless sensor node to enable real-time monitoring as well as remote sensor configuration. This paper presents the performance monitoring of a full-scale embankment constructed on a thirty-meter deposit of soft clay at a bridge replacement site in upstate New York. Prefabricated vertical drains (PVDs) and surcharge loads were used at this site to accelerate the consolidation of the soft clay deposit. Two thirty meter long SAAs were used to monitor the horizontal and vertical movement of the embankment. Comparative results between the SAA systems and traditional instrumentation are also presented.

Keywords: MEMS; settlement; construction monitoring; vertical drains.

© 2010 by Geotechnical Society of Singapore (GeoSS)