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920 Apollo Rd - Ltr re: Crane Study Permit#98147MEYER BORGMAN JOHNSON March 9, 2011 John Young Paramount Real Estate Corporation/TCN Worldwide 3601 Minnesota Drive, Suite 925 Bloomington, MN 55435 Dear Mr. Young: Crane Study for Apollo Industrial Park (mbj # 11.348.0) Eagan, Minnesota 81.04 PEA /r - E40 4014e7 As requested, we have studied the effects of the proposed crane on the existing building structure at the 920 Apollo Road facility. The proposed crane is an overhead crane with a three ton rated capacity, 248 feet of travel, and an approximate bridge girder span of 40' -3 ". The proposed crane runway is vertically supported on crane columns (by Stewart Engineering) bearing on the existing concrete slab -on- grade and laterally supported by the existing precast wall panels and structural steel building columns. Our understanding of the proposed crane is based on conversations with you and Mike Stewart of Stewart Engineering, and on drawings provided to us via e-mail that include the following: • Unsigned and undated existing structural drawings SO, S I and S2 prepared by Betker /Stangeland. • Unsigned architectural drawings Al thru A4 dated 01/21/11 prepared by WCL Associates, Inc. • Crane Clearance Diagram (one sheet) dated 01/19/11 prepared by Stewart Engineering and Sales Co. Load calculations were performed based on a 6,000 lb maximum wheel load per direction from Mike Stewart of Stewart Engineering & Sales in lieu of the 7,5001b maximum wheel load shown on Stewart Engineering's Crane Clearance Diagram. In addition, a crane railway self - weight of 99 plf was used based on conversations with Mike Stewart. Our calculations show the design crane structure loading onto the existing structure to be as follows: • Maximum vertical crane column reaction = 19,200 lbs • Transverse crane runway reaction to existing precast wall panels = 1,800 lbs • Transverse crane runway reaction to existing steel columns = 900 lbs • Longitudinal crane runway reactions to the existing structure were not calculated (x- bracing is to be provided by Stewart Engineering). In addition, we modeled the effect of the proposed crane loading on the existing building structure. Our findings and recommendations are as follows: • The existing structural steel columns (existing Grid D) are capable of safely supporting the transverse crane runway loading without additional reinforcement at an elevation of 22 feet above the finished floor elevation. The connection between the runway structure and the existing building columns (by others) should be detailed to allow for relative vertical deflection between the crane and building columns. 12 South Sixth Street, Suite 810 Minneapolis, MN 55402 www.mbjeng.com 612.338.0713 SEE STRUCTURE. John Young March 7, 2011 Page 2 of 2 The existing concrete pad footings supporting building columns (existing Grid D) are capable of safety supporting the vertical crane column surcharge at a distance of 2' from the existing column centerline (as proposed by WCL/Stewart). We recommend the Owner contact the original precast wall panel supplier and have them verify the capacity of the existing panels to safely support both the transverse loads from the crane runway and the lateral soil pressure caused by the vertical crane column surcharge loading (19,200 Ibs per crane column). We do not have sufficient information on the existing precast wall panels to be able to make this determination. We recommend an 18 "xl 8" base plate (3/4" minimum thickness) be used to support the crane support columns in lieu of the 10 "xl0" plates shown by Stewart Engineering in order to provide a safe effective soil bearing area in the likely case that the existing slab condition is not exactly as shown on the drawings. Common problems with slab -on -grade construction include variable soil compaction, uneven grading and misplacement of the reinforcement (mesh is often found in the bottom of the slab). The Owner should be made aware that while the use of larger base plates will reduce the risk of cracking, it will not eliminate it. Where cracking of the existing slab occurs, the stability of the slab should be monitored to prevent an unsafe condition from developing. If you should have any questions or co Sincerely, ey r Bo an Johnson tor, P.E. Proje t Eftgineer, Associate Daniel E Murphy, P.E. Senior P incipal Cc: file Date T ents regarding our findings, please do not hesitate to contact us. I hereby ce or report was direct supervi teed Professio the State of this plan. epecificati ed by me oz under my nd that I am a duly Regis - npineer under the laws of states.