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HomeMy WebLinkAboutEngineer's Field Observations 02.24.2012KURTZ & ASSOCIATES, 1NC. 5012 County Road 154 Glenwood Springs, CO 81601 STRUCTURAL CONSULTANTS Phone (970) 945 6305 189 MOSHER: Observations 02/24/2012 The floor elevation of 189 Mosher appears to be higher than the elevation of Mosher Ave. to the south of the building. On the north end of the building there are areas of localized, negative drainage, where the surface drainage appears to be directed towards the building. The building at 189 Mosher displays differential foundation settlement. The west side of 189 Mosher appears to have settled relative to the east, and that the north end has settled relative to the south. Along the length of the building the settlement appears to be relatively uniform. The exterior, precast, wall panels display some distress and potential panel -to -panel connection failure. On both the east and west walls three adjacent vertical panel joints display vertical cracking in the face slab of the wall panels directly adjacent to joint and/or separation of the panel -to -panel joint. ( West wall: see photo 1400jpg. East Wali: see photo 1407. jpg + 1409. jpg) The wall cracking widens at the top of the wall panels, indicating a differential settlement from north -to -south There is an exterior landing at a man door on the east side of the building, near the north east building corner. The landing is a concrete slab -on -grade which measures, in plan, 4'-0" x 4'-0". The slab appears to have settled differentially towards the building. At this time the slab is out of level, east -to -west, 6" in 4'-0". (See photo 1412.jpg) 1 tJecr 1/41v4g: 1.049. tioRr4 ! `e'ai-g" 12'-0" wide x 14'-0" high door LeAkl WesT *-c Rept 14eT 1/2.74de: Side Elevation : 5007-14 LtiJATo�) scale: 3/16" =1'-0" us, ei PiD S hag, 0 T-4" _{ ti f,iure po.der Leolt4 is A,JEsT L% Floor Plan • 8'-0"8'-0„ 64'-0" 8'-0" S.OG41 141745 : : s eRAKArQa c R.44.401,61 ►�v,� h�c.�ls7 P# JT_ I 1 I I I i I s E PARATokj AD4 Ae,r4r_ C RAC.Klai NIEL I � 01 o5NE `2. No�.Tu Wei 1/4-u/4' 4 8'-0"' 7'-4"" iwtrsJ iLEA,* fsioRTo f 'z 74$« KURTZ & ASSOCIATES, INC. 5012 County Road 154 Glenwood Springs, CO 81601 STRUCTURAL CONSULTANTS Phone & Fax (970) 945 6305 FIELD OBSERVATION REPORT To: Justin Thornburg 39 Goldfield Court Parachute, Co. 81635 Date: June 25, 2015 Re: 189 Mosher, Travelers highlands Industrial Park, Garfield County, CO. Brian Kurtz, P,E. of Kurtz & Associates, Inc. performed a structural inspection of the noted building on June 25, 2015. The noted building has suffered differential foundation settlement. The building measures, in plan, 64'-0" north -to -south by 30'-0" east -to -west. The exterior wall height of each building = 16'-0". The exterior walls are constructed of 8'-0" wide by 16'-0" high precast concrete wall panels. The roofs are framed with pre - manufactured wood roof trusses spaced at 24" on center, spanning 30'-0" east -to -west. The perimeter foundations were not exposed to view. Based upon previous observations which I have made of similar buildings in the Travelers Highland Subdivision, it can be concluded that the structure is founded upon a perimeter foundation system which is constructed of continuous concrete foundation walls (grade walls) and footings. Note that all of the building's loads (The building weight or dead load and the roof snow load) are supported on the perimeter foundation walls and footings. There are no interior supports. Given the height of the building, and the rigidity of the concrete wall panels, one is able to view differential movements of the walls. Note that some of the exterior wall panels have window openings and man -door openings which were formed into the pre- cast panels. The subject building has two (2) locations where the precast panel was omitted to accommodate a garage door opening: 1. There is a 12'-0" wide by 14'-0" high garage door opening centered on the north and south ends of the building, respectively. The interior concrete slab -on -grade floor at 189 Mosher displays differential movements. I utilized a surveyor's self leveling level to establish the amount of differential slab displacement. (2) The slab is divided with a series of construction joints. Joints running east -to -west across the building are spaced at 16'-0" on center. There are two (2) north -to -south joints dividing the slab in that direction into three (3) sections. The center section of slab is 12'-0" wide, and the east and west sections are 9'-0" wide. The floor slab displays significant differential settlement. The dominant settlement is down to the north: The floor slab slopes at an average rate of approximately 2.5% along its 64'-0" length. The secondary settlement is down to the west: While the center section of slab is generally higher than the slab at the east and west exterior walls, the settlement to the west is slightly more pronounced. The slab at the northwest corner of the building has experienced the most settlement. The slab in this corner of the building is approximately 2'-3" lower than the high point of the floor at the south end of the building. Note that the differential slab displacement at the perimeter of the building is directly related to differential settlement of the building's perimeter foundation system: As the perimeter foundation system has settled, it has pulled the interior floor slab down. The differential foundation settlement is being caused by the weight of the building and intermittent, excessive ground moisture. The natural, on sight, soils are fine grained silts and clays which are prone to settlement when wetted excessively. The building's weight is also a significant factor contributing to the differential settlements. Note that the building weight, including the foundation (concrete footing and grade wall), the 16'-0" high pre- cast wall panels, and the wood framed roof equals approximately 1300 PLF. At the interior slab construction joints there are a number of locations where the adjacent slabs are displaced slightly relative to one another. It appears that the interior slab has suffered a minor amount of frost heave. The garage door openings on the north and south sides of the building are much more flexible than the pre -cast wall panels. Consequently, much of the differential foundation movement is reflected in the noted door openings and framed section of wall: the door openings and the doors are out of square. RECOMMENDATIONS It is my professional opinion that the building, at this time, is in acceptable structural condition, and is not in danger of sudden collapse. Consequently, temporary shoring is not recommended at this time. The building owner, as part of his building maintenance program, should examine the precast wall panel to foundation wall connection all around the building. He should verify that continuous bearing of the panel is being maintained at the top of the (3) foundation wall and that there is no visible cracking or distress of the precast concrete where the panels are bolted to the foundation wall. At present, the surface drainage conditions are contributing to excessive ground moisture adjacent to the building. The present and natural site drainage is down to the south towards the Colorado River. Finish grades on the north side of the building and on the west side of the building should be improved as much as is practicable so as to direct surface moisture away from the foundation. The installation of drainage system which directs surface and subsurface water away from the foundation represents a proven method of mitigating future differential foundation settlements. In the case of the subject building, as the building owner, you may wish to consider the installation of a subgrade drainage system along the north, east and west sides of the building. As part of a building maintenance program, the drainage system could be installed to intercept and divert surface and near surface water. The drainage system should include an impervious membrane and a perforated dram pipe with a gravel and filter fabric surround. The drain pipe should extend well away from the foundation and carry the excess water away via a solid walled pipe. Continuous roof gutters are installed on the east and west sides of the building. Each gutter runs to a downspout at the south end of the building. The downspouts should be extended so as to deposit roof runoff as far from the building foundation as is practicable. If you have any further questions, feel free to call. Kurtz & Associates, Inc. Brian J. Kurtz, P.E.