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4.12.17_Letter MassDOT and Pan Am Review215 First Street, Suite 320, Cambridge, Massachusetts 02142 p | 617.497.7800 f | 617.498.4630 April 12, 2017 Tim Doherty Director of Rail Programs Rail & Transit Division MassDOT 10 Park Plaza Suite 4160 Boston, MA 02116 RE:Design Package for Review -Drainage Relocation Project Former Northampton Lumberyard (256 Pleasant Street) Dear Mr. Doherty: Kleinfelder is pleased to submit this design package for MassDOT and Pan Am review for the Drainage Relocation Project located at the former lumberyard site (256 Pleasant Street) in Northampton, MA. This review is related to the City’s Drainage Relocation Project and the adjacent rail road property known as the “MassDOT Knowledge Corridor” in Northampton, MA. We kindly request the review period for this package is two weeks due to the phasing and schedule of the site development project on the same site. The drainage relocation project will enable the site development project to commence. The drainage relocation for review is at the 100% DRAFT design level and is anticipated to be ready for bidding in May of 2017 with award to the contractor in June of 2017. The package for review includes the following documentation: x Response to Comments on the 60% design from a memo provided by HDR to MassDOT dated 1/12/2017. x 100% DRAFT Plans and Specifications for the Drainage Relocation Project which include Support of Excavation Design Plans for the Culvert work. x 100% DRAFT Specifications for the Drainage Relocation Project. We also respectfully request further guidance on the requirements that the contractor will be responsible to adhere to when working in the vicinity of or within the RR ROW so we can incorporate these requirements into the construction documents and avoid potential delays or work stoppages. We are looking to include at a minimum, the railroad insurance requirements, including Railroad Protective Insurance; coordination and costs for railroad inspection and flaggers. The work that we anticipate in the RR ROW includes the contractor establishing monitoring points in accordance with Section 7 of the MBTA Rail Road Directorate and for the contractor to perform survey location work within the RR ROW if required. The Drainage Relocation work itself is not expected to take place within the RR ROW as shown on the 100% design plans. Response to 60% Design Comments HDR Comment No. 1 - The location and elevation of the railroad tracks shall be determined with on the ground field survey and shown on the plans and sections. The rail road zone of influence should be revised accordingly on the sections. Tim Doherty April 12, 2017 Page 2 215 First Street, Suite 320, Cambridge, Massachusetts 02142 p | 617.497.7800 f | 617.498.4630 Response - Kleinfelder had initially depicted the tracks in the 60% design based on MassGIS information. As part of the 100% design, Kleinfelder has incorporated the track location survey information, which was collected by Bryant Associates in June of 2016 as part of the work on the Northampton Train Station. This information was provided to Kleinfelder by Bryant Associates via MassDOT. The 100% design plans presently show the updated track location and elevation information as noted on the existing conditions plan. If further track survey is required, the contractor will be asked to coordinate this effort. HDR Comment No. 2 - Sections should present the shortest distance (i.e. perpendicular to the tracks) between the tracks and box culvert and should measured on a skew. Response -The section views have been updated and are provided on the 100% plans. HDR Comment No. 3 - Sections shall be show the property line between the subject parcel and MassDOT property. Response -The section views have been updated to include the property line and are provided on the 100% plans. HDR Comment No. 4 - Either limits of work (excavation) or support of excavation associated with the box culvert construction shall be shown on the sections and plans. Response –The 100% plans show the approximate limits of work and support of excavation. HDR Comment No. 5 - As shown the railroad is impacted as the zone of influence from the railroad is undermined by typical section of the excavation trench. The designer shall be required to provide to the railroad prior to construction detailed plans and calculations for the support of excavation of any work that undermines the railroad zone of influence. Response –The initial approach was to have the contractor perform the design of the support of excavation (SOE). However, in recent discussions with the City, it has been decided to have Kleinfelder perform the design of the SOE. The SOE design is included as part of this package for MassDOT and Pan Am Review. HDR Comment No. 6 - The prosecution of the work required for the box culvert construction shall not encroach into the railroad right of way in any manner without MassDOT and railroad operator approvals. This includes storage of materials, access to railroad property with equipment or personnel. Access of railroad shall be noted to include the swing of any part of backhoes/cranes and other equipment over the property line. Notes stating such shall be added to the plans. Response -We have incorporated notes within the 100% drawings for the contractor to follow the MBTA RR Directorate. We have included language in the specifications to cover this item as well. Additional HDR Comments: Tim Doherty April 12, 2017 Page 3 215 First Street, Suite 320, Cambridge, Massachusetts 02142 p | 617.497.7800 f | 617.498.4630 The plans indicate a comprehensive subsurface exploration plan has been executed as part of the design effort. This effort includes soil borings, infiltration tests and monitoring wells conducted over an extended period (2013-2016) period of time. HDR Comment No. 7 - The designer shall indicate whether dewatering is required for box culvert construction and show approximate ground water elevations on the sections, if applicable. Response -Dewatering design will be required by the contractor. Groundwater information is available in the boring logs, which are included within the specifications. HDR Comment No. 8 - The designer shall indicate whether blasting and/or the removal of ledge is required for box culvert construction and show approximate ledge line on the sections, if applicable. Response –Based on the subsurface information compiled to date, we do not anticipate blasting and or ledge removal. There will be pile driving as shown in the SOE design. The contractor is required to monitor the tracks per MBTA RR Directorate. Proposed Future Retaining Wall As noted above, it appears this may be a phased project. There are lines and annotation on the plans and sections that indicate a proposed future retaining wall shall be constructed immediately adjacent to the common property line. HDR Comment No. 9 - To address the similar considerations relative to the future retaining wall as noted in comments above related to the culvert installation, it is recommended that the designer of the retaining wall and other proposed adjacent infrastructure be required to provide plans, elevations, sections and details of the proposed improvements for review by MassDOT. Response –This comment has been addressed by the designer of the retaining wall. See attached Souza True response letter dated February 15, 2017. If you have any questions, please do not hesitate to contact us. Respectfully yours, KLEINFELDER Joseph J. Maliawco, P.E. Project Manager cc: Dillion O’Toole, Pan Am Railways Wayne Feiden, City of Northampton David Veleta, City of Northampton Laura Baker, Valley CDC David Peterson, Kleinfelder file 215 First Street, Suite 320, Cambridge, Massachusetts 02142 p | 617.497.7800 f | 617.498.4630 Letter from Souza True and Partners, Inc. In response to HDR Comment No. 9 February 15, 2017 Davis Square Architects, Inc. 240A Elm Street Somerville, MA 02144 Attention: Mr. Darrell Aldrich Reference: Northampton Lumber Yard Site Retaining Wall – MassDOT Review 256 Pleasant Street Northampton, Massachusetts Dear Mr. Aldrich: As requested, Souza True has reviewed the comments provided by MassDOT in regards to the proposed drainage relocation and site retaining wall which are part of the Northampton Lumber Yard Project located at the above-referenced address in Northampton, Massachusetts. The MassDOT comments are contained in a memorandum prepared by HDR dated January 12, 2017. These comments are based on review of the 60% design documents prepared by Kleinfelder dated August 2, 2016 and are limited to the potential impacts the drainage relocation and site wall construction will have on the nearby MassDOT Knowledge Corridor railway. Souza True’s review of the HDR memorandum and subsequent responses contained herein are concerned with the site retaining wall only, which Souza True has provided structural engineering services for. The portion of the work for which Souza True provided structural engineering services consists of a cast-in-place concrete retaining wall. The wall is approximately 200 feet in length located at or near the eastern property line of the Northampton Lumber yard site, common with the abutting railway corridor. The proposed retaining wall will typically retain approximately 3’-0” of unbalanced fill with the high side grade sloping up and away from the proposed wall towards the existing railway tracks, which are at a higher elevation than the proposed new top of wall. The proposed top of wall will be between elevations 123.50’ and 126.50’, and the proposed bottom of new wall foundations will general extend to 4 feet below grade, with the lowest estimated bottom of footing to be at elevation 116.00’. Mr. Darrel Aldrich February 15, 2017 Page 2 The HDR memorandum is divided into several sections and enumerates several items / comments. The comments and questions are primarily related to the exact location and elevation of the new structures relative to the existing railway location and elevation, including the common property line location. The existing railway zone of influence and its extents as well as the limits of work and excavation support for new site structures are also of great importance. All of the items in the preceding paraphrase of the HDR memorandum were focused mainly on the new drainage relocation, which will be responded to by Kleinfelder (the drainage relocation designer). However, the final question (#9) contained in the HDR memo raises similar considerations for the proposed site retaining wall. The following discussion is provided by Souza True, as the designer of the proposed site retaining wall, to address the comments and concerns raised by MassDOT in the HDR memo. The site retaining wall design is documented in a drawing labeled “SW1” prepared by Souza True dated February 8, 2017, and this drawing shall be used as reference in the following: First, the exact location and elevation of the existing railway are unknown. There is a range of estimated elevations for the railway tracks, varying between elevation 133.00’ and 137.00’, but it is generally believed to be at elevation 135.00’ based on several corroborating sources (see Kleinfelder response to HDR memorandum). Also, the lateral distance relationship between the existing railway and the common property line are unknown at this time. Future on-ground survey (provided by others, not by Souza True) will be necessary to determine the exact locations. Souza True currently estimates a distance of approximately 22 feet between property line and railway tracks. The proposed new site wall will be at or very near (within 1 foot, approximately) of the common property line on the lumber yard site. The elevations of the proposed wall are specified above and on the SW1 drawing for the wall; the maximum proposed elevation is 126.50’ at top of wall and minimum of 116.00’ at bottom of footing. Based on the above dimensions and elevations, Souza True expects that the proposed new site retaining wall will be in the zone of influence of the railway tracks. The zone of influence for the tracks is assumed to be defined as a sloped line with a 2 horizontal to 1 vertical dimension extending outward from the track rails, based on the comments made in the HDR memorandum. The SW1 site wall drawing shall indicate the locations and elevations of the existing railway track on plan and in section. The section shall also indicate the approximate zone of influence of the railway tracks. These revisions shall be made to the drawings for future submission. Second, the proposed new site retaining wall will require excavation within the assumed zone of influence of the existing railway tracks. The selected contractor will be in responsible charge for the design and execution of any and all temporary excavation supports, as this is “means and methods” to the construction of the wall. Similar to Kleinfelder’s response to this issue, the contractor shall be required to submit the temporary excavation support plans and design calculations as required by the MassDOT comments. The approximate location of the temporary excavation supports Mr. Darrel Aldrich February 15, 2017 Page 3 has already been shown in section on SW1. The location of the property line and limits of work shall also be shown on the structural drawing for future submission. There are three other minor concerns in addition to the primary MassDOT concerns addressed above. Question #6 in the HDR memorandum concerns construction activities encroaching on the MassDOT right of way. The encroachment will be addressed for the proposed site wall by locating the wall such that the limits of work and proposed equipment access do not encroach on the right of way. Alternatively, the contractor shall be required to seek approval for any encroachment as their means and methods of construction dictate. For Question #7, minor ground dewatering shall be required by the contractor, as noted in the Preliminary Geotechnical Engineering Recommendations report prepared by O’Reilly, Talbot & Okun Associates, Inc. dated January 1, 2015. Regarding question #8, ledge removal will not likely be required as the depth to bedrock is estimated to be well below ground level, also as noted in the geotechnical report mentioned above. Finally, the structural design of the site retaining wall has taken into account the influence of the existing railway corridor and its site features. The slope of high side soil grade retained by the proposed wall has been assumed to create a 35° angle to horizontal to account for the relative difference in elevation between the top of wall and railway tracks. This results in a Rankine active lateral earth pressure coefficient of 0.82 calculated for determination of the lateral loads applied to the wall. In addition, an above grade surcharge load of 400 pounds per square foot starting at the face of wall and extending far afield has been utilized in the proposed retaining wall design to account for the heavy railway traffic loads. Please feel free to contact our office should you have any further questions or comments. Updated drawings with the revisions noted above shall be provided for the next submission to MassDOT. Sincerely, SOUZA, TRUE AND PARTNERS, INC. Christopher M. Motto, P.E. Jerome A. Yurkoski, P.E. Senior Structural Engineer Senior Principal