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07/27/05 Porrini/Extra MuckLeistiko Consulti From: "Phil Por" <phil@rpa-hln.corn> To: <Ieistiko@digisys. net> Sent: Wednesday, July 27, 2005 4:59 PM Attach: KCA-Letter050726.pdf; 050727mb—response.Itr.doc Subject: Kalispell City Airport - Extra Muck MmIl The muck excavation at KCA is causing some concem and a request for more money and contract time. 1*1ease read through the attached letters, one from Schellinger and the proposed response. Right now it looks like a $28K to $33K increase to take care of the poor saturated soils. Their prices seem reasonable. Since we need to keep the work progressing I'll need your recommendation of whether this needs be be written up as a Change Order and have it approved prior to the work being done or if we can get a verbal okay. morning after your review. Ps. There is a line item, valued at $13.5K (Prime Coat) that is most likely going to be waived and not applied. I Philip P. Porrini @ Robert Peccia & Associates P.O. Box 5653, 825 Custer Avenue Helena, MT 59604 (406) 447-5000 (406) 447-5036 fax (406) 439-8755 cell email: phil@rpa-hln.com The following section of this message contains a file attachment prepared for transmission using the Internet MIME message format. If you are using Pegasus Mail, or any another MIME -compliant system, you should be able to save it or view it from within your mailer. If you can -not, please ask your system administrator for assistance. information ----------- File: KCA-LetterO5O726.pdf Date: 27 Jul 2005, 16:56 Size: 2201114 bytes. Type: Unknown 7/27/2005 The following section of this message contains a file attachment prepared for transmission using the Internet MIME message format. if ou are usini Peiasus Mail or another MIME -compliant system - I WWAINII ---- File information ----------- File: 050727mb response.Itr.doc Date: 27 Jul 206, 16:57 Size: 37376 bytes. Type: Unknown OWNW, Schelfinger (,instruction; Co., finc P0BOX 39 C UTOE 59912- 039 OL !A FALLS, 1' 3 KY"IF i 1,-,G) 8'2-21z8 Tuesday, July 25, 2005 Brandon Theis Robert Peccia & Associates P.O. Box 5100 Kalispell, MT 59903-5100 Re: Kalispell City Airport — North End Surfacing Improvements Subject: Unsuitable Sub -grade Material Mr. Theis, This letter is in regard to Field Order and Field Directive #I, dated July 19, 2005. The original field order that was issued onsite stated that the sub -grade between approximately Station 11+00 and 12+50 on Taxiway "A" was pumping due to excessive sub -grade disturbance from the scraper traffic that was stripping topsoil in this area, and hauling excavation material to the designated waste area. Schellinger Construction was directed to avoid hauling across Taxiway "A" in these areas to prevent pumping of the sub -grade, and was notified that if any additional scraper traffic continued to cross through these areas that repairs required to the sub -grade material would be at the contractor's expense. Schellinger Construction agreed to avoid hauling through these areas to eliminate any additional damage to the sub -grade material. Schellinger Construction continued with the topsoil stripping for the building pads on both sides of Taxiway "E", as well as the alignment for Taxiway "E" and "D". While stripping the topsoil off of these areas additional pumping was beginning to occur in these areas as well. It was becoming very apparent that the sub -grade material was saturated with water and very unsuitable due to the high clay content in the material. In summary the soils on the North end of the project were pumping under light scraper traffic (stripping only), and these pumping areas were not due to "excessive sub -grade disturbance", but were unsuitable for any type of traffic load. Schellinger Construction was directed in the field by RPA to excavate out the areas that were pumping on Taxiway "A", and one at the intersection of Taxiway "A" and "C". The area of excavation at approximately Station 12+50 was 1497 SF and approximately 4'deep, equivalent to approximately 222 CY. It was apparent that the ground water level in this area was approximately 3' deep from the existing ground level, and that the soils at this level were very unstable due to the excessive moisture content in the clay type soils. Schellinger Construction placed stabilization fabric in the bottom of the excavation and was directed by RPA to haul native material from the excavation on the tie -down apron to replace the material that was removed. Over the next couple of days this area was static rolled with a smooth drum roller several times, and some elimination of the pumping was observed. Schellinger Construction was also directed to excavate out an area at approximately Station 11 +25 that was 1144 SF and approximately 2.5' deep, equivalent to 106 CY. Fabric was also installed in this area and native dirt from the apron was placed and compacted. In addition Schellinger Construction was also directed to excavate an area at the intersection of Taxiway "A" and "C' which was 1500 SF and approximately 2.5, deep, equivalent to 139 CY. This area has not yet been filled in with native material, and it is very apparent that the ground water has risen in this area due to the water displacement caused by the compaction on Taxiway "A". All of the waste from these areas was stockpiled and spread out to dry adjacent to the areas of excavation, and was later hauled of by scrapers into the designated waste area. Schelfinger Construction Co., Inc. Ro. BOX 39 COLUMBIA FALLS, tulff 59912-0039 �`K'X,J` f,�GE02-21188 C, I �F ��EORCGESCHMIDII Tuesday, July 25, 2005 Brandon Theis Robert Peccia & Associates P.O. Box 5100 Kalispell, MT 59903-5100 Re: Kalispell City Airport — North End Surfacing Improvements Subject: Unsuitable Sub -grade Material Mr. Theis, This letter is in regard to Field Order and Field Directive #1, dated July 19, 2005. The original field order that was issued onsite stated that the sub -grade between approximately Station 11+00 and 12+50 on Taxiway "A" was pumping due to excessive sub -grade disturbance from the scraper traffic that was stripping topsoil in this area, and hauling excavation material to the designated waste area. Schellinger Construction was directed to avoid hauling across Taxiway "A" in these areas to prevent pumping of the sub -grade, and was notified that if any additional scraper traffic continued to cross through these areas that repairs required to the sub -grade material would be at the contractor's expense. Schellinger Construction agreed to avoid hauling through these areas to eliminate any additional damage to the sub -grade material. Schellinger Construction continued with the topsoil stripping for the building pads on both sides of Taxiway "E", as well as the alignment for Taxiway 'E" and "D". While stripping the topsoil off of these areas additional pumping was beginning to occur in these areas as well. It was becoming very apparent that the sub -grade material was saturated with water and very unsuitable due to the high clay content in the material. In summary the soils on the North end of the project were pumping under light scraper traffic {stripping only), and these pumping areas were not due to "excessive sub -grade disturbance", but were unsuitable for any type of traffic load. Schellinger Construction was directed in the field by RPA to excavate out the areas that were pumping on Taxiway "A", and one at the intersection of Taxiway "A" and "C". The area of excavation at approximately Station 12+50 was 1497 SF and approximately 4' deep, equivalent to approximately 222 CY. It was apparent that the ground water level in this area was approximately 3' deep from the existing ground level, and that the soils at this level were very unstable due to the excessive moisture content in the clay type soils. Schellinger Construction placed stabilization fabric in the bottom of the excavation and was directed by RPA to haul native material from the excavation on the tie -down apron to replace the material that was removed. Over the next couple of days this area was static rolled with a smooth drum roller several times, and some elimination of the pumping was observed. Schellinger Construction was also directed to excavate out an area at approximately Station 11 +25 that was 1144 SF and approximately 2.5, deep, equivalent to 106 CY. Fabric was also installed in this area and native dirt from the apron was placed and compacted. In addition Schellinger Construction was also directed to excavate an area at the intersection of Taxiway "A" and "C" which was 1500 SF and approximately 2.5, deep, equivalent to 139 CY. This area has not yet been filled in with native material, and it is very apparent that the ground water has risen in this area due to the water displacement caused by the compaction on Taxiway "A". All of the waste from these areas was stockpiled and spread out to dry adjacent to the areas of excavation, and was later hauled of by scrapers into the designated waste area. Per our field meeting today with Brandon Theis (RPA), At Schellinger, Kyle Schellinger, and myself of Schellinger Construction it was agreed upon in the field that RPA would be forth coming with a directive to subex out all of the areas that are apparently pumping under the paved road section, and that these areas would be filled with onsite native materials without a layer of stabilization fabric. Schellinger Construction is in agreement that these unstable areas need to be repaired in order to provide a stable sub -grade material that will not move under the gravel and asphalt section, and to have a hard enough surface to achieve the required 100% compaction required on the gravel and asphalt materials. It has been proven in the field that the existing sub -grade in these areas can be compacted to the requirement of 95%, but these areas continue to pump and move even under the weight of the smooth drum roller. If the sub -grade is excepted in this state it will be very difficult to achieve 100% compaction on the gravels, and the integrity of the asphalt is liable to deteriorate due to the movement of the underlying soils. Schellinger Construction has also been directed, per Field Directive #1 to not utilize vibratory compaction on the gravel or asphalt material in order to avoid disturbance of the sub -grade. It will be very difficult to achieve 100% compaction on these materials by static rolling only. It was not specified in the original contract specifications that vibratory compaction could not be utilized on this project. If vibratory compaction is not permitted, Schellinger Construction will be required to spend more time and effort by static rolling, and should be compensated for this additional time and effort if this becomes a requirement on the project. Following are our unit prices for the muck excavation and soil replacement that that will be required in the areas that are unsuitable as directed by Field Directive #1 and the forth coming directive from RPA. * Muck Excavation P, Haul $ 6.35 per CY ® Fill Replacement in Subexcavated Areas $ 2.15 per CY * Additional Contract Time I Day per 500 CY of Excavation We due not agree that the original unit price of $ 5.50 per CY for excavation would be sufficient to cover the costs of the muck excavation and soil replacement. The unsuitable soils will have to be removed with an excavator, loaded into dump trucks, and hauled onsite. The incoming fill material will be stockpiled adjacent to the excavation with scrapers, but will have to be double handled and placed into the excavated areas with a dozer. This method of excavation is sufficiently different than excavating dirt with scrapers, placing it into an embankment, and leveling it with scrapers. It is our opinion that stabilization fabric should be utilized in the subex areas to provide some separation between the materials and to stabilize the base before placement of onsite native material. Schellinger Construction also recommends that some type of gravel material be imported and utilized as fill in the areas that are excavated. It is our opinion that replacing this unsuitable material with a similar onsite material will only temporarily repair the stability of the sub -grade. Schellinger Construction does not guarantee that the method of repair proposed by RPA will permanently repair this ongoing problem, and we will not be responsible for any additional repairs required if the proposed solution is unsuccessful. Please provide us with a detailed directive of how you would like to proceed with this problem. A timely response is requested in order to continue construction of this project. If you have any questions or require additional information please feel free to give me a call. Sincerely,/ Z, Marc R. Blanden Project Manager Schellinger Construction Cc., Inc.