Laserfiche WebLink
We are looking at two parking designs, one the sheer walls stay and the other moves the sheer <br />walls. Issues concerning drive aisle, tree wells, parking under planters, and ventilating the <br />~ structure were discussed. It may require that we go deeper under perimeter on the sidewalk <br />area. We will need clearance for ventilation ductwork, if at depth of 24-36" anywhere else in the <br />building, the whole structure would have to drop 2-3 feet. Further discussion explored <br />possibilities available to handle this issue and it was recommended that it can be handled and <br />worked through in future mechanical/electrical meetings. <br />Environmental <br />Parking structure issues were tabled to revisit environmental issues. Kathleen was asked Why <br />are we eacavaNng 16 feet overall for removal purposes if we are only going down 12-13 <br />feet? Will there be de-watering, backfill and compaction involved? Kathleen made a <br />decision based in part on geological information that showed granular composition at 16 feet. If <br />you hit river rock, it is useless to remediate. It was noted that the top slab is at 10'4", 4" slab <br />and then footings below that. No underslab grades? <br />R.G. asked if this was a legal, DEQ or policy issue? Kathleen reiterated it is a <br />recommendation to give to the team and the type of impacted soils are governed by different <br />rules. Chevron will be handled by different rules. Byron clarified that if we are going to <br />overdig, it would make a big difference. The redesign depth of the basement is in process. <br />Other issues impacting depth would depend on how faz out to the property line we go, the tree <br />well needs, impacts on vehicles. <br />What is the best guess on grade dig? Leonard answered 10'4" is one we can live with, but we <br />~,,,i may need to go an additional foot or two to accommodate the tree wells. 10'4" is regulated by a <br />minimum 8 foot clearance in the bus mall for drainage. Will we still have varying heights in <br />parking? Yes <br />There was some confusion in what was being said. Using a grade dig of 10' 8" ptus or minus <br />and Kathleen's recommendation to dig to 16 feet, at what point do we make decision about <br />how far to dig once decision on P1 is made? Kathleen's decision is driven by geology. The <br />first approach had to do with river rock. The second with overall worker health and safety in <br />exposing portions of contaminated soils to accommodate footings. The third issue was having <br />no firm design plan at this time to work from. Whatever she did would accommodate any other <br />changes that may take place. This was a point that would allow any further variations in the <br />design. Her ma~mum was 15 feet and she added another 1 foot to accommodate any other <br />unknown that came up. <br />We need to finalize P1 underground drainage. The design of the building doesn't affect the <br />remediation. Should we not just remediate it? You wouldn't just stop at 10 feet if you hit <br />contaminated soils. We are looking at granular materials and we don't really know if it is river <br />rock. The decision will be based on the kind of impact. Some requirements will allow <br />impacted soils to remain, be capped and monitored. <br />Additional discussions ensued regarding cost issues if removing soils unnecessazily. Use of <br />native soils is an important issue for structural. We can refine definitions and can refine <br />remedial activities. Initial instruction to excavate to base level and then get individual <br />instructions given as you go. We are more interested in spread of impact than in depth of <br />Page 3 of 9 <br />