Geotechnical Investigation for the K-7 and I-70 Interchange Bonner Springs, Kansas

摘要

The K-7 and I-70 interchange is a proposed project set forth to accommodate the growing city of Bonner Springs, KS as well as increase the traffic flow into Kansas City. Currently this is the second (2nd) busiest interchange in all of Kansas City. Approximately 145,000 vehicles a day travel through the existing major system to system interchange. The design for the proposed interchange includes expansion of existing I-70 and K-7 to accommodate the traffic volume projected in the future as well as construction of new ramps and collector roads. The project has ten (10) proposed phases. To date, KDOT has completed Phases 1 through 3, which are associated with the expansion of I-70 to six lanes, construction of new loop ramps in both the northwest and southwest quadrants of the existing K-7 and I-70 Interchange and two (2) bridge replacements at Riverview Ave. and 118th St. We have portions of Phases 4 and 9 completed and are preparing to begin work on the remainder of Phase 4 and Phase 6. The management of what has been done and what needs to be done has been a challenging obstacle that we faced since the project began. Since our geothechnical investigation has started, we have had to be flexible on which Phase we could work on due to landowner permission, right of way acquisition, designer needs, and information availability. We have also had to revisit and re-drill due to changes in design and site access. The geology of the site has posed many obstacles alone. In this area, the Tonganoxie Sandstone Member lies disconformably on the Stanton Formation where it cuts through the Iatan Limestone and Weston Shale Members. This disconformity developed by the infilling of existing deep erosional channels during the deposition. The Tonganoxie Sandstone encountered across the majority of the site contains thick sequences of fine grained, cross-bedded sandstone with several thin, non-continuous, interbedded sandy shales. To date there have been over 200 power auger borings performed for approximately 5 miles of surface geology investigation and 3 bridge foundation investigations. KDOT’s geotechnical investigation on the proposed infrastructure continues to be done as needed through this developing suburb of Kansas City. Construction is set to start early in 2013 on Phase 2 and letting date of mid 2013 for Phases 1 through 3. The remaining phases do not have let dates at this time. As the state of Kansas grows, so does the need for development and improvement of our infrastructure. As geologists, we need to ensure that we provide the most accurate preliminary design information possible.