SEISMIC DESIGN BIOGRAPHY SUMMARY OF THE Brad is a Principal with Palmer New bridges over Kentucky KENTUCKY LAKE Engineering Company and Lake and Lake Barkley are in works in the Winchester, Ken- the United States’ most seismi- AND LAKE tucky office. He has a BSCE cally active area in the East, the BARKLEY from the University of Cincin- New Madrid Seismic Zone. Basket handle arches were cho- nati, an MSCE from the Univer- APPROACH sen for the navigation spans SPANS sity of Colorado, and a PhD with more than a mile of ap- from the University of Ken- proach spans crossing the lakes. tucky. His wife finally said Because these structures will enough and made him get a real serve as a main route for evacu- job. ations and first responders, the David Rust is a Project Manag- Kentucky Transportation Cabi- net (KYTC) designated them er with Palmer Engineering also "essential" for seismic design. in the Winchester office. He To remain functional after a earned a BSCE from the Uni- large earthquake, site-specific versity of Cincinnati and an hazard analyses, extensive field MSCE from the University of testing, and site-specific re- Kentucky. David is Engineer of sponse analyses provided com- Record on the Lake Barkley ap- prehensive input for structural proach spans. design. Response spectrum BRAD ROBSON analyses with linear foundation Kyle McLemore is a Structural models were used in prelimi- Engineer in the Nashville office nary design to screen numerous of Palmer Engineering. He approach span arrangements holds a BSCE from the Univer- and narrow to viable alternates. sity of Florida and an MSCE Time history analyses deter- from Vanderbilt University. mined the final layout which Kyle led the seismic analysis ef- was then evaluated by account- forts for this complex and chal- ing for nonlinear soil response, lenging design project. p-delta effects, potential plastic hinging, as well as the seismic dampers that were added to en- hance performance. DAVID RUST KYLE MCLEMORE SEISMIC DESIGN OF THE KENTUCKY LAKE AND LAKE BARKLEY APPROACH SPANS Location and History As two of the longest bridges in the Commonwealth of Kentucky, each represents a major investment in US 68 / KY 80 crosses over Lake Barkley and Ken- Kentucky’s transportation infrastructure. The sites tucky Lake in western Kentucky. These two bridges are near one of our country’s most seismically haz- serve as gateways to the Land Between the Lakes ardous areas; the New Madrid Seismic Zone (LBL) National Recreation Area (Figures 1-2). At (NMSZ). In the event of a major earthquake, this more than 170,000 acres, the LBL is one of the larg- corridor across the two lakes will serve as an evacu- est undeveloped areas in the eastern United States. ation route and allow first responders to access areas The existing Eggners Ferry Bridge over Kentucky between the LBL and the Mississippi River. Balanc- Lake (Figure 3) was constructed in 1932 across the ing cost and performance, KYTC designated these Tennessee River and is 3348 feet long. In 1933 bridges as "essential" for seismic design to remain Congress established and President Franklin D. functional after a large earthquake. Roosevelt signed the Tennessee Valley Authority (TVA) Act to control flooding on the Tennessee River, provide navigable waterways, and generate electricity. The Kentucky Dam project to impound Kentucky Lake was authorized by Congress on May 23, 1938; construction began in 1938 and was com- pleted in 1944. Consequently, in 1943 the bridge Land Between the Lakes was temporarily closed and raised 22 to 25 feet to accommodate the lakewaters. Kentucky Lake is the largest TVA reservoir at 160,000 acres and the larg- est artificial lake in the eastern US by surface area. In a similar fashion, the existing Lawrence Memori- al Bridge over Lake Barkley (Figure 4) was con- structed in 1932 across the Cumberland River and is 3045 feet long. Barkley Dam was authorized in the Figure 1: Project Location (Google Maps). River and Harbor Act of 1954; construction began in 1959 and was completed in 1964. The transfor- mation of the Cumberland River into Lake Barkley necessitated raising the Lawrence Memorial Bridge in 1963. Project Locations Originally built for lighter and narrower traffic, the New Madrid, MO existing structures have only 20 feet of clearance for the two lanes of opposing traffic. With recreational boaters, campers, and today's semi-truck fleet, inci- dents of mirrors slapping and accidents are not un- common. Furthermore, the navigational clearance for barge and other lake traffic is substandard; Egg- ners Ferry Bridge provides approximately 350 feet Figure 2: Project locations relative to New Madrid, of navigation width while Lawrence Memorial Missouri (Google Maps). Bridge provides only 320 feet. The new basket han- dle arch spans will provide more than 500 feet of navigable width. Page 1 of 8 quake in 1895. The NMSZ is the most active seis- mic area in the United States east of the Rocky Mountains with numerous small earthquakes rec- orded each year. The faults are poorly understood because they are covered by approximately 200 feet of alluvium and are not present on the ground sur- face as other faults are, such as the San Andreas. The locations for the two bridge replacements are approximately 80 miles from the town of New Ma- drid. Figure 3: Existing Eggners Ferry Bridge. Bridge Locations Figure 4: Existing Lawrence Memorial Bridge. Figure 5: USGS seismicity of the New Madrid Seismicity Seismic Zone (circle is proportional to magnitude). New Madrid, Missouri is the site of some of the largest earthquakes ever experienced by modern-day Pre Design Americans, outside of Alaska. A series of large quakes, three of which are believed to be larger than Planning for replacement of the aging bridges over magnitude 7.0, struck the region in the winter of the two lakes in western Kentucky began over two 1811-1812. At this time, the area was the frontier of decades ago. In 1995 FHWA approved the first en- settled land so few people experienced the greatest vironmental assessment for the project. After a few effects of the quakes. Some who did reported the delays, in 2006 KYTC selected the team lead by land rolling in waves while others reported tempo- Michael Baker International with major sub- rary backward flow and waterfalls on the Mississip- consultant Palmer Engineering to perform type se- pi River for several hours. Many landslides, fissures, lection, preliminary and final design services. sandblows, lateral spreads, subsidences, and uplifts were found after the great quakes. Reelfoot Lake Public Involvement near the Tennessee-Kentucky border was created af- A Citizens Advisory Committee provided the pro- ter the land subsided from the earthquakes. ject team guidance. Additionally, a multitude of data Seismic activity in the NMSZ did not end after the was collected at public meetings through anony- great quakes. As seen in Figure 5, a magnitude 6.3 mous electronic polling. Public preferences for spe- quake occurred in 1843 followed by a magnitude 6.6 cific and general appearance were incorporated into Page 2 of 8 final recommendations. During this months-long From results of the load test program, it was deter- process, the project team refined engineering con- mined that the piles should be driven open-ended cepts and estimates so the final selection balanced with a constrictor plate inside to force the piles to the public interest for aesthetics and economy. plug. Ideally, the position of the internal constrictor plate would force the piles to plug as the tip pene- The broad public involvement process undertaken in trated the hard chert layer. One of the world's largest the type selection study included presentation of hydraulic pile hammers (IHC S-800 double-acting renderings, gathering public preferences, and evalu- hydraulic hammer with a ram weight of 88.15 kips ating the economics of the many varied alternates. and a rated energy of 590 kip-ft) was used to drive On July 14, 2009 Governor Steve Beshear an- the piles deep enough to achieve the required verti- nounced that Basket Handle Arch Bridges were cho- cal and lateral capacities. sen to be constructed over the navigation channels at At Lake Barkley, hard limestone is approximately Kentucky Lake and Lake Barkley. These signature 90 to 100 feet below the water surface for most of ‘gateways’ to the Land Between the Lakes National the length of the crossing. Water depth is about 55 Recreation Area would be the first of their type in feet in the former Cumberland River channel and 5 Kentucky and some of the first for the country. to 20 feet deep in the former riverbank areas. Be- cause of the shallower depths to hard rock, drilled Geotechnical Investigation shaft foundations were chosen for Lake Barkley. Although only about 8 miles apart, the subsurface Approach spans will have 7-foot diameter drilled conditions of the Kentucky Lake and Lake Barkley shafts socketed into rock with permanent steel cas- bridge sites are very different. In 2009, KYTC se- ings. Voids were encountered during the exploratory lected a geotechnical team lead by H.C. Nutting drilling in this karstic region. Techniques for reme- (now Terracon) with major sub-consultant Florence diating voids during construction were devised and & Hutcheson, Inc. (now HDR, Inc.) for final design included in the bid documents. services. The geotechnical team built on previous geotechnical investigations and formulated an ex- Seismic Design Criteria tensive field exploration program. AASHTO (1) provides specific provisions for bridg- Many soil borings, rock core borings, standard pene- es classified as regular, and provides general guid- tration tests, cone penetration tests, seismic cone ance for critical and essential bridges.