This manual describes use of a new hybrid autonomous crack and structural response monitoring (ACSM) system. It is designed as a low cost alternative to the research grade version employing SOMAT’s eDAQ data recording system. The concept is to combine a new field portable, 24 bit, 12 channel seismograph with...
Non-destructive evaluation (NDE) techniques have been used for a number of years to provide quality control of construction procedures for drilled shafts and driven concrete piles. In particular sonic echo and impulse response methods have been used extensively to check lengths and continuity of newly-installed foundations. In recent years, the...
Public concern over construction vibration-induced cracking has led to the development of a radically new approach to vibration, an autonomous crack comparometer (ACC). This thesis chronicles the first step of developing equipment and software necessary for this system. The new system will automatically compare longterm weather induced micrometer changes in...
This thesis summarizes two further developments of the Autonomous Crack Monitoring (ACM) system, which facilitates simultaneous measurement of crack response to environmental changes and various dynamic events. The first component was measurement of crack responses in three different materials and locations in a residential structure subjected to ground vibrations produced...
This thesis summarized the qualification and testing of two commercial Autonomous Crack Monitoring (ACM) systems for use in measuring micrometer displacement of cracks. Qualification involved the assessment of both laboratory and field performance in a residential structure subjected to nearby quarry blasting for the production of roadway aggregate. Aggregate and...
The finite element method is used to investigate failure mechanisms in pin-hanger connection in aging highway bridges. Bridge pins and hangers are typically considered as critical elements whose failure may result in partial or entire collapse of the structure. The primary function of a pin-hanger connection is to allow for...
The U.S. has 542,000 bridges that consume billions of dollars per year in construction, rehabilitation and maintenance funds and which are the lifelines of U.S. commerce. The 1992 ISTEA (fntermodal Surface Transportation Efficiency Act) mandates the implementation of a quantitative computerized bridge management system by I 996. A prime need...
This presentation contains information on the keynote paper "Health Monitoring of Early Age Concrete". The presentation was delivered by Surendra P. Shah at CONSEC'04 in Seoul, Korea on June 30, 2004.
Acoustic emission (AE) testing was used to identify the source of audible “bangs” generated during opening and closing of a large, double-leaf rolling-lift bascule bridge. The data were analyzed using a combination of well-established AE
techniques, including first hit analysis (FHA), planar location analysis, and linear location analysis. The FHA...
The in-depth inspection by WIDOT detected two sites that had visible cracks in the stiffener-to-hanger diaphragm welds, the east side of Hanger 6 in the north tie girder, and the east side of Hanger 4 in the south tie girder. Additionally, many ultrasonic indications were detected by WIDOT in the...