The purpose of this comparative field qualification is to demonstrate the new Kelunji EchoPro
hybrid ACSM system and its performance relative to the eDAQ and eko Motes systems. These three
systems are installed at a test site in Sycamore, IL, adjacent to an active quarry. Data for this report was...
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...
Autonomous Crack Monitoring (ACM) and Autonomous Crack Propagation Sensing (ACPS) are two types of structural health monitoring in which characteristics of cracks are recorded over long periods of time. ACM seeks to correlate changes in widths of cosmetic cracks in structures to nearby blasting or construction vibration activity for the...
This appendix contains all software used to program the MICA2 motes for Version 1 of the MICA2-based wireless ACM system. This appendix is organized by software directory and only the modified files are included.
The notion of blasting, even in a controlled setting such as a limestone quarry, can be alarming to residents and business owners within earshot. Because humans are inherently sensitive to blast-induced vibrations, they perceive that the structures in which they live in are equally sensitive. The goal of this project...
Cosmetic and structural cracks are a large concern for homeowners. Although these cracks can develop from a variety of causes: differential foundation settlement, occupant activity, climatological effects, as well as dynamic events, people tend to look to dynamic events like blasting, construction, or traffic vibrations to be the culprit. This...
This paper describes the technology and methods deployed in the continuous autonomous remote monitoring of cracks in interior and exterior walls of a residence near a limestone quarry. The objective is to quantitatively compare crack response due to blast-induced ground motion to that induced by diurnal temperature changes, weather fronts,...
In this paper vibratory crack response is compared to that produced by volumetric changes in foundation soils induced by natural events. These natural phenomena include changes in the water table, changes in soil moisture, and formation of ice lenses to name a few. Previous papers have compared vibratory responses of...
This paper describes the technology and methods deployed in the continuous autonomous remote monitoring of cracks in interior and exterior walls of a residence near a limestone quarry. The object is to quantitatively compare crack response to blast-induced ground motion to that induced by diurnal temperature changes, weather fronts, and...
Micro-meter dynamic crack responses in a two story structure to rock blasting- and wind gust- excitation are compared to those induced by long term climatological effects. These measurements substantiate the conservancy of the 12.5 mm/s (0.5 in./s) blasting vibration control to protect residential structures against cracking. The test structure was...
A unique judicial opportunity allowed measurement of the response of three cracks in residential structure to blasting for underground aggregate mining. Instrumented cracks were located in the interior basement CMU mortar and upstairs dry wall as well as exterior brick work. The dynamic environment was unusual. Even though the blasting...
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...
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...
Crack and structural response to construction trench blasting was measured in a woodframe house with a stucco exterior. Blasts at distances between 232 m to 368 m produced peak particle velocities (PPV) and air blast over pressures (AB) of 9 mm/sec and 0.02 kPa (123 dB), respectively. Structural response velocities...
Miniaturized, wireless instrumentation is now a reality and this thesis describes development of such a system to monitor crack response. Comparison of environmental (long-term) and blast-induced (dynamic) crack width changes in residential structures has lead to a new approach to monitoring and controlling construction vibrations. In wireless systems transducer power...
In early 2001, a sinkhole formed directly under State Road 66 near the city of Sebring in Highlands County, Florida. The Florida DOT built a land bridge over the sinkhole and the road was reopened to traffic. Since SR-66 is an important regional trucking route, it was decided that the...
Cosmetic cracks are very common in structures, and most of the time they remain unnoticed and do not decrease the structural integrity. Although these cracks are unremarkable and barely noticeable, occupants become concerned about these cracks when construction occurs nearby. In order to investigate the true nature of these cracks,...
All structures have cosmetic cracks, which have no influence on structural integrity and usually remain unremarked until the structure’s occupants sense ground vibrations. Such vibrations are often associated with engineering activity, but are rarely responsible for cracks. However, this is difficult to prove without scientific basis. Automated Crack Monitoring (ACM)...
Autonomous Crack Measurement (ACM) facilitates simultaneous measurement of crack response to environmental changes and vibrations produced by various construction activities. Dual-purpose crack displacement sensors measure crack response, while the vibration environment is defined by standard seismological transducers and the weather environment is defined as changes in temperature and humidity. This...
This appendix synthesizes micrometer changes in crack width in response to both long term (environmental) and transient (blast vibration) of four of the structures in the main body. The appendix begins with a description of the genesis of the study and instruments employed. Response of the distressed wood-framed structure in...