Tunnel Business Magazine

AUG 2018

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Page 28 of 43

Sandy Hurricane Restoration of Hugh L Carey Tunnel Fire Protection System The contract documents required the fire protection to protect the precast reinforced concrete divider slab separating the ventila- tion plenum and the roadway surface from progressive collapse. The fire protection also needed to be easily removed for inspec- tion of the tunnel structure and to withstand routine cleaning and maintenance with a power scrubbing brush machine. The existing tunnel ceiling was covered with a ceramic coated steel architectural panel. These panels were removed before the fire protection was installed. The existing ceiling slab has venti- lation and lighting recesses. These recesses vary throughout the tunnel, but there is a repeating pattern through more than 80% of the tunnel. The contract documents provided an example layout for fire protection boards, but it was the contractor's responsibility to do the final fire protection panel layout with approval by the owner. The contractor chose to do a 3-D scan survey of the tunnel to develop accurate data for all of the recesses and to help deter- mine an overall layout pattern. The tunnels had several horizontal curves and compound curves ranging from 1,885 to 3,000 ft radii. The placement of the boards through the curves were negotiated in tangent sections. The layout in the curves required a tapered course to be cut-to-fit every 22 ft length of tunnel. Because of clearance issues and the maximum fire protection thickness was limited to less than 22 mm (0.875 in.). Due to the need for routine mechanical washing of the ceiling, a two-part ep- oxy based top coating was required to protect the fire protection boards. Initially, a dark gray ceiling was chosen to keep the ceiling dark and reduce the claustrophobic feeling of being in an enclosed space. By the ceiling being dark in color, the height of the tunnel is not easily recognized. After coating the boards gray, the owner de- cided to change the portal areas c tch the new blue, yellow and cream-colored wall tiles. The coating was a two-part epoxy water-based coating. The coating specification was of one coat primer plus two coats of col- ored epoxy water-based coating and one coat primer plus three coats colored epoxy water-based coating. The coating selected was from a U.K. manufacturer who had served the tunneling sector for over 40 years. The contractor chose a 22-mm matrix engineered calcium sili- cate aluminate board (Promat H) utilizing the Post Fixed method. The boards were pre-cut at the factory to fit the layout of the tun- nel then shipped to the U.K. for coating. The coated fire protection boards were butt jointed and placed directly against the concrete on the tunnel ceiling and anchored using mechanical anchors. The owner looked at the U.S. manufactured stainless steel an- chors available and determined along with the contractor to us a "nail head" type anchor. The anchor chosen was specifically de- signed for anchoring fire protection boards to tunnel ceilings and walls. This anchor at this time is only made in Europe. These an- chors have a closer profile to the board and the owner liked the aesthetic look by not having the nuts protruding into the tunnel profile. The owner did require a larger anchor 0.375 in. (10 mm) diameter in each corner with a nut with nylon insert and wash- er to ensure a conservative approach and a small tradeoff on the aesthetic look. All mechanical anchors including 1.125 in. (30 mm) were stainless steel Grade 316. Thermal Justification of the System Existing test data provided sufficient thermal information on system performance of the proposed system along with Promat's oftware, developed and validated by Efectis, to comply with the requir A 502-2011. The intended anchors including the 0.375 in. (10 mm) were fire tested to RWS time/temperature curve prior to this project per A-502 requirements and satisfied the thermal performance for the Promat T 22 mm boards and anchors as a system. Experiences Sandy Restoration of the Hugh L Carey Tunnel The biggest challenge on the project was ensuring the boards could be cut to size and coated prior to installation. Even though the 3-D scan survey was detailed, verification in the field after the board layout was required to ensure the boards would fit. The portal areas, approximately 600 ft at each end, was built by open-cut construc- tion. These areas had large light recesses and vent areas all varied in spacing. The portal areas required the fire protection panels to be cut to fit in the field. The balance of the tunnel, which was constructed ents and light recesses were in line and had a repetitious pattern with only a few anomalies. The main part of the tunnel used four different sized boards (A,B,C,D). The A panels ran along the outside of the tunnel to the edge of the recessed light. The B panels were placed between the lights. The C panels were placed between the vents. This left two rows of D panels running down the centerline of the tunnel. The lengths of the panels in the longitudinal direction of the tunnel were 1,200 mm (47.25 in.), the standard width of the fire protection boards selected. This article was submitted by Promat , a leading supplier of fire protection products. For information, visit www.promat-see.com. TUNNELINGONLINE.COM TBM: TUNNEL BUSINESS MAGAZINE // AUGUST 2018 F E A T U R E S T O RY 2 9

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