<p>Geotechnical engineers are taking core samples of the bedrock where designers hope to put the foundations for the new Mississippi River Bridge. Randy Hitt, Mississippi River Bridge deputy project director for the Missouri Department of Transportation (MoDOT), said that so far the core samples seem to consist of good, solid rock.<br /><br />Hitt said engineers will use information obtained from the geotechnical survey to design the foundations for the two piers that will support the bridge. They will decide, for example, whether they have to drill a shaft into the bedrock to support the piers or if they can use caissons, which rest on top of the bedrock.<br /><br />In order to minimize obstruction to barge traffic, the new bridge will have a clear span of 1,500 feet between the two foundations &ndash; the longest clear span across the Mississippi River in Missouri, Hitt said. In comparison, the clear spans of the Alton and Quincy bridges are about 800 feet and the clear span of the Cape Girardeau bridge is 1,150 feet, he said. Engineers think the two towers to support the cables that will hold up the bridge will have to be about 400 feet tall to support that long of a clear span, he said.</p>
<h4><img alt="Drilling for Mississipi River Bridge" class="image-left" height="476" src="/images/uploads/drilling3.jpg" style="float: left;" width="253" />The new Mississippi River Bridge will touch down in Missouri just to the left (south) of the cement silos in the background. The cement silos belong to Continental Cement Co.</h4>
<p>&nbsp;</p>
<p>The geotechnical team assessing the bedrock includes people from HNTB, TSI, and Geotechnology Inc. Massman Construction provided the barge that served as a drilling platform. Geotechnology provided the drilling rig.</p>
<p style="text-align: left;">In 2001, Illinois and Missouri 
											received approval for a new 
											Mississippi River Bridge and 
											associated roadways (<a href="http://www.newriverbridge.org/initialphase.asp">shown on a map which can be viewed through this link</a>) . The components of the 
											project are:</p>
<ul style="text-align: left;">
<li>
<p align="left">Relocated I-70 
												in Illinois, north of its 
												current location</p>
</li>
<li>
<p align="left">A new, 8-lane, 
												I-70 Mississippi River Bridge (revised from the original to four lanes)</p>
</li>
<li>
<p align="left">An interchange 
												in Missouri with existing I-70 
												near Cass Avenue</p>
</li>
<li>
<p align="left">An improved 
												I-55/64/70 Tri-Level Interchange 
												in East St. Louis</p>
</li>
<li>
<p align="left">A connection 
												between the existing I-55/64/70 
												Interchange and the relocation 
												of I-70 called the I-64 
												Connector</p>
</li>
<li>
<p style="text-align: left;">Improvements to 
												ramps at the west side of the 
												existing I-55/64/70 Poplar 
												Street Bridge in Missouri</p>
</li>
</ul>
<p style="text-align: left;">The two states lacked sufficient 
											funding to construct all components 
											of the project at the same time. The 
											estimated cost of the Ultimate 
											Project Concept is between $1.8 
											billion and $2.2 billion. The scope 
											of work announced on February 28, 
											2008 is the first phase of the 
											project. This phase is 
											operationally independent since it 
											can be funded and built to function 
											as a viable transportation facility. 
											See the <a href="http://www.newriverbridge.org/initialphase.asp"> Proposed 
											Initial Phase</a> for 
											details.</p>
<p style="text-align: left;">.</p>