Division of Structural Design Geotechnical Branch Presented By: Bart Asher What is Geotechnical Engineering? The art of molding materials we do not wholly understand into shapes we cannot precisely analyze so as to withstand forces we cannot really assess, and done in such a manner that the community at large has no reason to suspect the extent of our ignorance. 1
Physiographic Regions Kentucky has a diverse topography that demands in-depth investigations. Karst (Sinkholes and Caves) 2
Branch Organization The Geotechnical Branch is one of the three Branches in the Division of Structural Design BRANCH MANAGER STRUCTURES ROADWAY & SOILS LAB CONSTRUCTION & MAINTENANCE GEOLOGY DRILLING & INSTRUMENTATION The KYTC Geotechnical Branch is involved - cradle to grave. If we throw something over the fence we have to go pick it back up. Project Initiation Try to supply the best information available to your geotechnical team! Advance Situation Folders are GREAT! 3
http://transportation.ky.gov/structural-design/pages/geotech.aspx Project Initiation - Like to have 6 month lead for small projects and 8-10 month lead on large projects things are now usually compressed. We can help you estimate R/W needs early on so you can start the purchase process. Project Initiation Site variability can be a real issue!!!! 4
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Other information needed. Need extra time if railroad present. Pass along any environmental problems. Help with property owner problems may need to use 10 day notice. (please let us know if they are armed) Special Requests Is there funding? Time Frame? 9
I saw the drillers leave, where is my report? Abbreviated Geotechnical Work Flow Chart Site visit ideally during the drilling phase, but also may be done at other times. Lab Testing (Rock) Logging Rock Cores Receive Rock Quantity Sheet from Consultant Prepare/Draft Receive Geotech Request w/ required information Prepare Boring Plan Schedule Drilling Drilling Lab Testing (Soil) Cut stability analyses Cut Slope Recommendations (RSD, Rock Slope Design report) Issue RSD Evaluate Rock Quantity Sheet Embankment Stability & Other Analyses Prepare Roadway Report; Draft Roadway Sheets Issue Roadway Report Contract Project using Statewide Geotechnical Engineering/Lab Testing Contract (Most phases of geotech may be individually contracted except drilling.) Statewide Drilling Contract Contract Soil Testing using Statewide Geotechnical Engineering/Lab Testing Contract (Most phases of process may also be individually contracted except drilling.) If Changes Either: 1)Revise Report OR 2) Go back to start (Depends on extent /type of changes) Geotechnical Analyses: Receive Geotech Request w/ required information (i.e. Advance Folders with structure sizes & locations) Prepare Boring Plan Schedule Drilling Drilling Lab Testing (Soil) Drafting for Structure Bearing Capacity, Pile Drivability, Pile / Drilled Shaft Capacity Settlement Slope Stability Prepare Structure Report Issue Structure Report Lab Testing (NOTE: Start of structure (Rock) investigations normally lags Logging Rock roadway phase.) Cores THEN YOU GET IT! 10
Updates What s New! Special Notes Compactive Effort When placing Granular Backfill proper compaction is critical!!!!! 11
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Where is the structural Granular Backfill? 13
Where s the geotextile fabric? 14
Settlement and the BUMP Too many new bridges have issues at the bridge ends. Combination of settlement of the foundation soils and the embankment. The settlement in the embankment can be directly correlated to how well it was installed. 15
Hard to predict and control foundation soil settlement but we try! Construction oversight and control required to control embankment settlement Let s try something new! Bridge Location Logan Co. KY 79 16
Bridge Side View (270 Long) Bridge Layout 17
Geosynthetically Confined Backfill 18
Install Geofoam Install Geomembrane 19
Compacting Crushed Stone Layer Installing Instrumentation 20
Settlement Sensor Monitoring GRS and Embankment Settlements Liquid Level Adjustment for Settlement Sensors 21
9/27/14 8 10/07/14 8 10/17/14 17 10/28/14 2 11/07/14 11 11/17/14 20 12/19/14 14 12/29/14 23 1/09/15 8 1/19/15 17 1/30/15 2 2.0 South Bound GCS Settlement (South End) GCS Settlement (in.) Temperature ( C) 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0-0.2 28.0 18.0 8.0-2.0-12.0 11/1/2014 Open to traffic Bottom West Upper 7 West Under Deck DateTime KYTC Wall Policy KYTC, in conjunction with KTC, is working on a Policy for Wall use in Kentucky 22
Down-hole camera - the Geotechnical Branch now has 3 down-hole cameras. We put them in our core holes to look at karst features, etc. Barren Co. I-65 over 31W Over 30 foot void 23
Communication is KEY!! We will need to help each other through the process by sharing information, getting holes staked, asking questions (both ways)! We re with the Government and we re here to help you. No. really.. If in doubt ALWAYS contact us about any Geotechnical matters. We are here to assist YOU, because we work for YOU! 24
I will hang around for Questions. 25