BELOW
THE SURFACE TransEd Valley Line LRT Project
1 TransEd Valley Line LRT Project Rock Sample Preparation Announcements Upcoming Events
1ST QUARTER / 2018
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In Edmonton, Alberta, TransEd Valley Line LRT is building a light-rail transit (LRT) connecting Mill Woods to downtown Edmonton with approximately 13 km of light-rail. This stage of the project includes 11 stops, an elevated station incorporating transit center and Park & Ride, and a transfer point to the existing LRT at Churchill Square. The project consists of constructing two, one-mile long tunnels under the center of Edmonton. The underground work includes bored tunnels and station excavations. Since the work takes place in an urban setting, the protection of existing structures and buried utilities is critical to the successful completion of the work. Geocomp monitored construction activity to help the contractor control the excavation and tunneling work and mitigate the risk of unexpected movement to adjacent buildings and utilities. We also provided instrumentation and monitoring for the one mile of twin bored tunnels using our iSiteCentral™ GIS web-based
software to provide real-time assessments of construction related activity. iSiteCentral integrated data from more than 2,000 sensors with settlement measurements and performance data from the Contractor’s own tunnel monitoring regime. The software also incorporated installation documentation and photos to better centralize all instrumentation information and make it readily accessible for reporting and review by TransEd. Geocomp installed a combination of manual survey and automated instrumentation to best suit the project’s monitoring requirements. A combination of radios and cellular modems were used to transmit data to the servers and iSiteCentral data management center, allowing near real-time viewing of data by anyone with an internet connection and the correct login credentials. Geocomp continues to monitor the tunnel post construction and has started monitoring the bridge construction for the project.
TECHNOLOGIES TO MANAGE RISK FOR INFRASTRUCTURE
Don’t Let Your Rock Strength Results Come Up Short Specimen Preparation is Key If your project requires rock compression testing by ASTM D7012 Methods A through D then end preparation by ASTM D4543– Preparing Rock Core as Cylindrical Test Specimens and Verifying Conformance to Dimensional and Shape Tolerances MUST be performed to produce suitable specimens. If tests are performed on specimens without preparing the core to ASTM D4543 tolerances, the results are not considered reliable and will produce lower values of compressive strength than a properly prepared sample. Each specimen must be machined to produce flat and parallel ends with perpendicular sides.
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Typical result used to confirm end flatness, 1 parallelism, and perpendicularity Preparing specimens on automated surface grinder
Confirming rock core meets ASTM tolerances
At GeoTesting Express, we always provide a report verifying the compression test specimen’s conformance to the dimensional and shape tolerances required by ASTM D4543. This provides you with the assurance that your results are as accurate as possible. Underestimating rock compressive strength can result in specifying the wrong equipment, increased excavation time or advance rates, and change of condition claims. Having the testing done correctly the first time can make a big difference in keeping project costs down. Below is an example comparing the results of a properly prepared sample vs. saw cut ends. 1. Compressive strength measured on six specimens of the same rock. Three specimens were saw cut specimens with no additional machining and three were prepared in accordance with ASTM D4543. 2. The unconfined compression results for the saw cut specimens had an average unconfined strength in the range of 20,000 psi with a standard deviation of 3,000 psi. 3. The unconfined compression results for the specimens meeting the ASTM D4543 tolerances had an average unconfined strength in the range of 30,000 psi with a standard deviation of only 200 psi. 4. Comparing the results shows the importance of quality end preparation. The specimens meeting the ASTM D4543 tolerances were 50% stronger than the saw cut specimens (30,000 psi vs. 20,000 psi). Unconfined Compression strength is one of the most important characteristics you can determine from the rock you are working with. Without the correct value, all other calculated properties and determinations are flawed.
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TECHNOLOGIES TO MANAGE RISK FOR INFRASTRUCTURE
ANNOUNCEMENTS Geocomp Welcomes Geocomp is pleased to welcome Aaron Epstein, who is heading up the Consulting Division in our Atlanta office, as our new Southeast Regional Manager. Mr. Epstein will be managing our efforts to establish and grow Geostructural engineering services in the Atlanta area, in addition to developing opportunities for Instrumentation & Monitoring services. He joins us from United Consulting, where he worked for the past 27 years, most recently serving as United’s Geotechnical Practice Leader and Program Manager on a number of geotechnical projects. He holds multiple state PE licenses and graduated with a Civil Engineering degree from Union College.
Accomplishments Geocomp is proud to announce another one of our engineers, Justin Robichaud, has officially received his professional engineering license in Massachusetts. Justin has been with Geocomp for 6 years and works primarily with our Geostructural Engineering and Instrumentation and Monitoring Groups.
In addition, Mir Fazlul Karim, an Engineering Geologist for GeoTesting Express, recently has become a licensed Professional Geologist. He has a MSc in Geology and Engineering Geology and has been with GTX for 11 years.
TECHNOLOGIES TO MANAGE RISK FOR INFRASTRUCTURE
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125 NAGOG PARK ACTON, MA 01720 T (978) 635-0012
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UPCOMING EVENTS Look for Geocomp and GeoTesting Express at the following upcoming trade shows:
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SEI Structures Congress (Presenter - Tom Weinmann) April 19-21, 2018 Fort Worth, TX USSD Conference and Exhibition (Exhibitor) April 30-May 4, 2018 Miami, FL Geo-Shanghai (Exhibitor) May 27-May 30, 2018 Shanghai, China Geotechnical Earthquake Engineering and Soil Dynamics Conference (GEESD) (Exhibitor and presenters W.Allen Marr and Kaveh Zehtab) June 10-13, 2018 Austin, TX International Bridge Conference (IBC) (Presenter - Tom Weinmann) June 11-14, 2018 National Harbor, MD North American Tunneling Conference (Exhibitor) June 24-27, 2018 Washington, DC Performance & Interpretation of Interface/Direct Shear Testing Workshop (Presenter - Gary Torosian) June 27, 2018 San Diego, CA w w w. g e o c o m p . c o m
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TECHNOLOGIES TO MANAGE RISK FOR INFRASTRUCTURE