Loading...
HomeMy WebLinkAboutPermit Correspondence 2007-10-16 .a K & A Engineering, Inc. P.O. Box 23624, Eugene, OR 97402 521 Market St., Suite B, Eugene, OR 97402 (541) 684-9399 Voice (541) 684-9358 FAX engineering October 16, 2007 Mr. Jeff Towery 6883 Forsythia Street ,Spnngfleld, OR 97478 Project: 223.06 Subject. Special inspection - foundation repair Spnngfleld permit no COM2007 -01346 6883 Forsythia St., Spnngfleld, OR PURPOSE AND SCOPE As requested, K & A Englneenng, Inc has made several Inspections of the subject foundatIOn repair project currently underway. The purpose of our Inspections were to review work completed, provide recommendations to the contractor for reqUired changes or modifications, and to ensure that the work completed met the specifications and Intent of the repair plan. This project Includes repair of the foundation of the west side of the garage only and Installation of drainage along the west side of the residence. This repair plan does not include underpinning or repair of other parts of the foundation INSPECTIONS Subsurface Drainage System We Inspected the new subsurface drain system as It was constructed This system was installed according to our specifications and recommendations. The trench extended below the ground surface to native undisturbed sandstone The side of the trench facing the foundatIon extended through approximately 2-feet of saturated organic clays located on the surface of native sandstone The trench depth ranged from 4 to over 6-feet in depth. A significant amount of water was drained from the organic layer dunng construction. The perforated trench drain pipe was connected to a solid drain pipe which was routed to the curb weep hole on the south Side of the street at the west side of the driveway West Garage Foundation Shonng and Removal of EXlstmg Footing and Slab The west garage wall and roof structure was shored and separated from the foundation and approximately 10.6- feet of the west footing and stem wall was removed, extending from the west Side of the portal frame at the garage opening to the man door. See the attached As-BUilt Repair Plan Additionally, a portion of the eXisting intenor concrete slab-on-grade was removed. K & A Engineering, Inc. After removal of the slab and existing foundation, the west portal frame footing and wall were repositioned to a plumb condition. Helical PIer Installation Three helical piers were installed at the locatIons shown on the attached As-Built Repair Plan. Two of the piers support a preconstructlon liT" bracket to be embedded Into the new concrete grade beam. The thIrd pier, located at the remaining existing portal frame foundation, supports a conventional steel bracket Due to the location of large boulders In the bedrock, the pier locations and helix configurations were modified from the onglnal repair plan We evaluated the static load capacity of the piers, as Installed, and have determined that the available load capacity exceeds the reqUired capacity. See Table 1 for a summary of the pier installatIOn. Table 1 - Helical Pier InstallatIOn Summary Required Allowable Minimum Pier Description Installed Installation Load Load and Location Depth, ft. Torque, k-ft Capacity, kips Capacity, kips 12" /14" Pier with 9.5' 6.8 170 <3.0 standard bracket at eXIst. Footing near NW Corner 8" / 10" Pier with 90 6.8 82 5.7 "T" bracket near center of new grade beam 12" Pier with "T" 9.0 66 6.9 1 1 bracket near south end of new grade beam Concrete Grade Beam A new concrete grade beam was constructed with the dimensions and reinforcing meeting our onglnal speCifications ThiS grade beam was attached to the remaining existing portal frame foundation at the northwest corner. The grade beam was attached to the existing foundation uSing 4 - 5/8" diameter grade 60 steel dowels that extended a minimum of 7 -inches Into the eXisting concrete. The grade beam was reinforced according to the project design and speCifications. C(Jpple Wall The eXisting framed cnpple wall supporting the floor of the residence along the south side of the garage was repaired according to our plans SUMMARY AND RECOMMDATIONS ThiS report documents our Inspections made of construction for the subject project. Work completed as of the date of thiS report Includes construction of an extenor perimeter subsurface drain system, installation of three (3) new helical piers, cripple wall repaIr, and a new concrete grade beam The construction of these elements Project. 223.06 Client. Towery 6883 Forsythia St , Spnngfleld, OR Page 2 of 3 October 16, 2007 K & A Engineering, Inc. was made In accordance with our design or, In the case of changes, was made with our approval and according to modified design recommendations We recommend acceptance of these elements, as constructed, by the local building official. The project IS not yet completed, and we anticipate making at least one more inspection report based on additional site Inspections Thank you for the opportunity to be of service. Please call me If you have any questions. Sincerely, Project: 223.06 Client Towel}' 6883 Forsythia St , Spnngfleld, OR Page 3 of 3 October 16, 2007 , k.a engineeflng geotechnical/civil engineering Eugene, OR 97408 541 684 9399 541 684 9358 fax " Project: 6883 Forsvthla St. Client: Towrev Job No: 223.06 Date: 9-28-07 Sheet. 1 of 1 ( \ ~-~ ~r-~~ ' r r _ '1 1 r -- - - - - - _...1, ,L_ - - -- - - --I I'r--------J L_________~ I , , , 1 I I , I I NEW CONC SLAB " V SAWCUT EXIST SLAB 193' REPAIR CRIPPLE WALL SUPPORTING FLOOR REPLACE STUDS@ 16" 0 C I , -~ APPLY 1/2" CDX SHEARTHING I NEW GONC I NAILED USING 8d @ 6" 0 G GRADE BEAM WEST / GARAGE WALL " ~~~~~~~~~,,~~I I ,----- l I I 1 I , _I , L_____, , , I L_____, I 1 I ~ I L---l I: ::~ L---l LJ I /1 ~ L_-, 1 :~ ii ~~:1 ~_+- - "" "" I 1 L______~ ~~- ~ N L~____~~____~-1 o ~ <( UJ co UJ Cl <( a: (!:l to ~ o 0 (J N ~ <D UJ Z o N ~ <D o 0> SAWGUT EXIST FOUNDATION DOWEL GR BEAM TO EXIST GONG USING 2 . #4 EPOXY INTO EXIST CONG 0') AS-BUILT REPAIR PLAN ~ 111=81 & STEEL HELICAL PIER WITH PIER BRACKET AT EXISTING FOOTING <8 STEEL HELICAL PIER WITH "T" FITTING SUPPORTING NEW CONCRETE GRADE BEAM