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SCHEMATIC DESIGN REPORT

Grandview Parkway Tunnel

September 2, 2011

Prepared for:

City of Traverse City / Traverse City DDA

400 Boardman AvenueTraverse City, MI 49684

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Copyright 2011 by Northwest Design Group, Inc. This document is an instrument of service belonging to

Northwest Design Group Inc. It contains privileged information pertinent only to the project named hereon,

and it is intended for the sole use of the client named hereon. It is not intended that this document be reused

or reproduced without permission from Northwest Design Group, Inc., nor that it be used in the preparation

of derivative works based on its content.

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TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 General1.2 Project Description & Scope

1.3Existing Information

2.0 SITE CONDITIONS AND CONSTRAINTS

2.1 Surface Conditions2.2 Subsurface Conditions

3.0 EXISTING UTILITIES

3.1 Electric3.2 Water3.3 Sanitary Sewer3.4 Storm Sewer3.5 Gas, Phone and Cable TV

4.0 DESIGN STANDARDS AND ELEMENTS

4.1 Design Standards4.2 Design Elements

1. Tunnel Width2. Tunnel Height3. Tunnel Length4. South Approach5. Design Load6. Roadway Pavement7. Trail Pavement8. Groundwater Consideration9. Excavation Support10.Snow Melt system11.Tunnel Stormwater Drainage12.Tunnel Water Service13.Tunnel Power Distribution14.Tunnel Lighting15.Security Camera System16.Wind Turbine System17.Maintaining Traffic

4.3 Aesthetic Considerations1. South Approach2. Tunnel3. Open Space4.4 Construction Budget

5.0 RECOMMENDATIONS

APPENDIX A: SCHEMATIC DESIGN PLANS

APPENDIX B: SCHEMATIC DESIGN ESTIMATE

APPENDIX C: MDOT PERMIT APPLICATION CORRESPONDANCE

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1.0 INTRODUCTION

1.1 General

This report summarizes Northwest Design Groups (NDG) schematic design-phase findings for theproposed Grandview Parkway Tunnel, located between Hall Street and Union Street along Grandview

Parkway, in Traverse City, Michigan. The purpose of this report is to summarize site conditions, providedesign alternatives, and present our recommendations for the proposed tunnel. Our services wereauthorized by our agreement with the City of Traverse City, dated March 24, 2011.

1.2 Project Description & Scope

We understand that the proposed tunnel is conceived to cross beneath Grandview Parkway (US-31) in agenerally north-south direction, aligned with a roughly 25-foot wide corridor between two existing buildings on the south side of US-31. The tunnel will provide safe pedestrian passage between theWarehouse District and the Bayfront. The south approach to the tunnel will be a ramp, sloping downwardfrom the existing grade, near Garland Street to an elevation low enough to pass beneath the highway withsufficient headroom. The existing building on the east side of this south approach is expected to remain.

To the west, a new hotel is planned. The tunnel itself is conceived as a pre-cast concrete box structure,placed in sections, in an open excavation across the Parkway and the TART Trail on the north side. Thenorth approach to the tunnel has been conceived to provide a fairly broad area opening to and graduallysloping up to the waterfront, with a stairway providing direct access up to the TART Trail. Existingprimary power lines, water main and services, and other utilities are located in the tunnel south approachcorridor and on the north side of US-31.

The project is located in Section 3, T27N, R11W, City of Traverse City, Grand Traverse County,Michigan.

1.3 Existing Information

The City of Traverse City/DDA provided the following information and data: Report of Geotechnical Engineering Exploration for the Proposed Grandview Parkway

Pedestrian Tunnel, Traverse City, Michigan. Prepared by Gosling Czubak Engineering Sciences,Inc. for the Traverse City Downtown Development Authority and City of Traverse City, DatedFebruary 2011.

Project Environmental Assessment for Proposed Pedestrian Tunnel, Grandview Parkway,Traverse City, Michigan. Prepared by Gosling Czubak Engineering Sciences, Inc. for theTraverse City Downtown Development Authority, Dated March 2011.

Site topographic survey. Completed by Mansfield & Associates for Traverse City DDA, DatedMay 2009.

NDG completed additional topographical survey on May 2-3, 2011, and attended meetings with the Hotel

Indigo developer and the Citys consulting engineer for the Garland Street project in order to coordinatedesigns and gather additional information.

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2.0 SITE CONDITIONS AND CONSTRAINTS

2.1 Surface Conditions

The proposed tunnel will cross beneath Grandview Parkway, known also as US-31. At the location of thecrossing, Grandview Parkway is a four-lane, concrete-surfaced Urban Other Principal Arterial (National

Functional Classification), maintained by the Michigan Department of Transportation (MDOT), and withan average daily traffic (ADT) of 27,292 in 2009 based on MDOT Bureau of Transportation PlanningAverage Daily Traffic Report. MDOTs right-of-way at the crossing is 66 feet wide. The roadway isrelatively straight and level through the project area with concrete curb and gutter on each side andconcrete sidewalk immediately behind the back of curb on the south side of the road.

The south approach to the tunnel is through a 25-foot wide vacant lot between existing buildings. On thewest side, 223 West Grandview Parkway, the existing building is a single-story brick building, currentlyhousing several businesses. This building is proposed to be demolished and in its place will be a newfour-story hotel. The exact location of the new building is yet to be determined. The building on the eastside of the corridor, 221 West Grandview Parkway, is also a single-story brick building. Bay WestAntiques currently conducts business in this building and the building is currently slated to remain. The

building is located on the property line and is in relatively poor condition, exhibiting several cracks in themasonry exterior. The depth of the footings is unknown, but is likely less than 3 feet below groundlevel.

A non-motorized path, the TART Trail, runs parallel to the north side of Grandview Parkway, about 7 to8 feet behind the back of curb. The trail is 8 feet wide and has a hot mix asphalt (HMA) surface. Northof the trail, the Open Space Park slopes gently down to West Grand Traverse Bay, approximately 250 feetto the north. This property is the former site of the Traverse City Light and Power Bayside Power Plant.

2.2 Subsurface Conditions

Based on the geotechnical report prepared by Gosling-Czuback Engineering Sciences, Inc., the soils

underlying the alignment consist predominately of loose to dense sand with various amounts of gravel.The borings encountered up to 12 inches of topsoil. Boring SB-2 encountered 9 feet of very loose sandymaterial containing trace clay and wood, characterized as uncontrolled backfill.

Groundwater was encountered in the borings at depths of about 14 feet below the existing ground surface,roughly correlating to the level of Grand Traverse Bay. At the date of drilling, Grand Traverse Bay was atan elevation of 577.2 relative to Traverse City Datum (NGVD 29). Based on US Army Corps ofEngineers projections, Lake Michigan water levels can be expected to be in the range of 577.5 to 578.8(NGVD 29) at the time of construction (assumed to be summer 2012). The maximum recorded level ofLake Michigan was 582.9 (NGVD 29). It is likely that groundwater levels will approximate the elevationof Lake Michigan.

The geotechnical report provided recommendations for site preparation and foundation bearing pressureswhich will be considered as the design progresses. It did not provide lateral earth pressures for design ofretaining walls.

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Gosling-Czubaks environmental assessment report concludes there is a moderate likelihood of soilcontamination impacting the proposed tunnel construction. Possible contaminates might include volatileorganic compounds (VOCs), semi-volatile organic compounds (SVOCs), metals, and cyanide. Similarly,the report finds that groundwater encountered during tunnel construction and use will likely containcyanide in levels exceeding regulatory limits, and may also contain VOCs, SVOCs, and metals. Inaddition, one of the soil borings drilled for the geotechnical study encountered unidentified odors,indicating possible petroleum hydrocarbon contamination.

The project environmental assessment completed by Gosling-Czubak indicates the likelihood of soil andgroundwater contamination at levels exceeding regulatory limits. Therefore, we concur with the reportsrecommendation of additional characterization of soil and groundwater to facilitate planning formanagement and disposal during construction. We recommend that the City/DDA procure the services ofa competent environmental consulting firm to complete this work.

Several subsurface utilities are located at or adjacent to the project site/alignment. Most significantly,these include a 12-inch water line running along the center of the south approach corridor and a set offour electrical conduits about 3 feet further east. Other water, electric, gas, and communications lines arelocated in the Garland Street and Grandview Parkway rights-of-way, as well as the south approachcorridor.

3.0 EXISTING UTILITIES

The existing utilities are shown on sheets C-101 and C-102 in Appendix A, and are described below.

3.1 Electric

Traverse City Light and Powers existing electric facilities pose significant impacts to this project, as theyconflict with the proposed tunnel alignment/severely limit the useable width of the right-of-way. Thereare existing underground electrical lines running north/south in multiple concrete-encased conduits thatare located in the 25-foot wide right-of-way and cross to the north side of the Grandview Parkway. NDGworked with TCL&P to expose the top west corner of the concrete encasement in 3 locations betweenGrandview Parkway and Garland Street. A vacuum truck, operated by Team Elmers, was used to expose

the concrete. The depth and locations of the concrete encasement were then recorded by NDGs surveycrew. The top west corner of the concrete encasement is about 14-feet east of the west right-of-way lineand 3-feet below the existing ground.

The Bayfront Study did not anticipate relocation of the electrical facilities would be required to constructthe tunnel. Based on the actual location, the electrical may remain in place with modifications andconstraints to the proposed tunnel design, or, in the alternative, they may be relocated. The preliminarycost estimate by TCL&P for relocation is $400,000. We are in the process of confirming this withTCL&P.

There are also existing electrical lines running east/west north of the Grandview Parkway. See sheets C-101 and C-102 in Appendix A. We expect that these lines can be relocated under the tunnel or behind thetunnel headwall.

3.2 Water

The City has an existing 16-inch cast iron watermain with lead joints that runs east-west on the north sideof Grandview Parkway. There is also a 12-inch watermain running north-south along the middle of the25-foot right-of-way and crossing Grandview Parkway. Both watermains are in direct conflict with theproposed tunnel alignment.

We understand that the watermains (16-inch and 12-inch) are planned to be replaced by a new watermainextending south on Hall Street, east on Garland Street and north on Union Street. This work scope is

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included in Greenan and Associates, LLCs Summary Report of Streetscape Improvements dated April 26,2011.

3.3 Sanitary Sewer

The City has an existing 8-inch clay sanitary sewer line that flows via gravity toward the west on thenorth side of Grandview Parkway. This line will conflict with the proposed tunnel. The start of this mainis near the intersection with Garland Street to the east.

We understand that the City plans to construct a new sanitary sewer main on Garland Street. This workscope is included in Greenan and Associates, LLCs Summary Report of Streetscape Improvements datedApril 26, 2011.

3.4 Storm Sewer

The Michigan Department of Transportation (MDOT) has a storm sewer system along GrandviewParkway that flows west from the Garland Street intersection, and is in conflict with the tunnel. Werecommend requesting authorization from MDOT to abandon the portion of storm sewer that exists eastof the tunnel, and picking up stormwater in new catch basins just west of the tunnel. The schematic designestimate for the tunnel project includes abandoning this portion of the storm sewer.

3.5 Gas, Phone and Cable TVThere are no active gas lines in conflict with the tunnel project. The project will include a service to thenorth side of the Parkway if a heated sidewalk deicing system is used.

Phone and cable television lines will require coordination and minor relocations during construction ofthe tunnel.

4.0 DESIGN STANDARDS AND ELEMENTS

4.1 Design Standards

The following standards will be considered in the tunnel design:

American Association of State Highway and Transportation Officials (AASHTO)LRFD BridgeDesign Specifications, 2010;

AASHTO Guidelines for Geometric Design of Roadways, 2004; AASHTO Guide for the Development of Bicycle Facilities, 1999; AASHTORoadside Design Guide, 3rdEdition 2006, with updated Chapter 6; Department of Justice 2010 ADA Standards for Accessible Design & Guidance on the 2010

ADA Standards for Accessible Design, September 15, 2010;

MDOTRoad Design Manual; MDOTBridge Design Manual; MDOT 2003 Standard Specifications for Construction; MDOT/MSP 2005 Michigan Manual on Uniform Traffic Control Devices for Streets and

Highways;

MDELEG Michigan Building Code, 2009.

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4.2 Design Elements

4.2.1 Tunnel WidthThe tunnel width requirements vary depending on what types of users are accommodated. Pedestrianwalkways should have an 8-feet minimum width, and multi-use or bicycle trail facilities should have a14-feet minimum width, per AASHTO recommendations. Based on City/DDA input, we understand that

bicycles should be accommodated with this project. A 14-foot clear width for the tunnel is proposed toaccommodate bicycles.

4.2.2 Tunnel HeightThe minimum tunnel height for bicycle facilities is 8-feet. Where practical, a height of 10-feet is desirablefor adequate vertical shy distance. For pedestrian use, a minimum height of 7.5-feet is required. Weunderstand that the City/DDA desires as much vertical clearance as is possible. The maximum tunnelheight will be controlled by the clearance required above the tunnel for pavement structure and the lengthavailable to the south to provide ADA access. Coordination with the future hotel in the southwestquadrant and future groundwater levels also need to be considered. Future groundwater levels could beover 5-feet above the tunnel walking surface. Based on our current understanding of the design factors,we expect the tunnel height to be between 8 and 9 feet.

4.2.3 Tunnel LengthThe tunnel length is set by space needed for Grandview Parkway (including a possible future median) andthe TART Trail (including minimum 5-feet clearance to future road and 3-feet minimum clearance torailing). These spaces add up to a total length of about 88-feet.

4.2.4 South ApproachThe hotel foundation wall will form the west side of the approach. A wall will be required on the east sideto retain the adjacent soil, which supports the TCL&P electrical conduits and the existing building. Weunderstand that the hotel developer adjacent to this project plans to allow the south tunnel approach toextend 4-feet onto that property, which will make it possible to construct the tunnel without relocating theelectrical lines (the electric manhole south of the Parkway will still need to be reconstructed). See Section

4.3 Aesthetic Considerations for discussion about the impact of this option to the design.

4.2.5 Design LoadThe tunnel will be designed for AASHTO bridge design loads (specifically HL-93 or HL-93 Modified)because the road pavement will be placed directly on the structure. MDOT may require modifications tothis loading, depending on the outcome of ongoing adjustments to their standards.

4.2.6 Roadway PavementBased on preliminary discussions with MDOT, we expect the new Grandview Parkway pavementstructure to consist of a 6-inch (minimum) reinforced concrete slab cast directly on the precast concretetunnel, with 9-inch thick approach slabs, extending 20 feet east and west of the tunnel. The vertical andhorizontal alignments of the Parkway will match existing. Pavement that is replaced as a result of

construction beyond the approach slabs will match the existing pavement structure.

4.2.7 Trail PavementThe trail pavement for the tunnel and approaches will be concrete. The concrete will be reinforced andtied to the wingwalls and site retaining walls to provide resistance to the buoyant forces of futuregroundwater. The concrete will also accommodate a snow melt system. The TART Trail passing over thetunnel on the north side will consist of hot mix asphalt (HMA) wearing surface on gravel base and sandsubbase, 10-feet wide.

4.2.8 Groundwater Considerations

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As discussed above, groundwater levels will likely mirror Lake Michigan elevations. Duringconstruction, with lake levels potentially as high as 578.8 (NGVD 29) and excavations as deep as 575.5(NGVD 29), water depths as deep as 3.3 feet can be expected during construction. Culvert bedding,provided it is a coarse, uniform aggregate material, can be placed in the wet. Other dewatering can likelybe accomplished with a system of sumps and pumps, which are typically effective for depths up to about3 feet below groundwater. Where excavations are deeper, additional dewatering and possiblygroundwater cutoff (e.g. sheet piling) may be warranted. As dewatering water may contain contaminants

above regulatory levels, disposal will require careful consideration.

Lake Michigan levels, and therefore groundwater levels, are likely to someday return to elevations nearthe maximum recorded level. We recommend designing for levels approximately 1 foot above themaximum recorded, for a design level of 583.9 (NGVD 29). The tunnel should be designed to be dry atthese water levels. We do not consider pumping as a feasible method to prevent groundwater intrusioninto the tunnel as groundwater at the site is potentially contaminated and because energy costs would beexcessive. Rather, we recommend waterproofing the tunnel and approaches. The waterproofing systemshould consist of HDPE membrane as this material is durable and resistant to petroleum products.Geocomposite drainage panels should be placed against the structure on each side to capture any leakageand to provide a cushion to protect the membrane. Nonwoven geotextile should be placed between thestructure and the membrane; both top and bottom, as well as outside of the membrane to further protect it

from punctures. Special connection details will be designed for the south approach, where the approachwill likely share a wall with the proposed hotel.

The tunnel and approaches must also be designed to resist uplift forces associated with buoyancy effects.This resistance will be provided by the structure weight, as well as the weight and friction of the adjacentsoil. The tunnel structure itself will have sufficient weight to counteract these loads. Similarly, it appearsthat the south approach will easily meet the required resistance. We expect that the north approach willrequire additional measures to add requisite uplift resistance. The area with depth below elevation 583.9(NGVD 29) should be minimized. Concrete floor slabs may be thickened and extended beyond the outerretaining walls to capture the overlying soil weight. If necessary, tie-down anchors, such as helical plateanchors, can be used where the soil and structure weights are not adequate.

To relate the proposed floor elevation with existing features, NDG obtained elevations at the existingCass Street Pedestrian Tunnel, sidewalk under the Union Street Bridge / Boardman River and concreteplaza at Cass Street Bridge / Boardman River. See table below:

Description Elevation (NGVD 29)

Proposed Tunnel Floor 578.2

Existing Cass Street Tunnel Floor 580.5

Existing Sidewalk under Union Street Bridge 582.8

Existing Plaza at Cass Street Bridge 581.7

4.2.9 Excavation SupportThe majority of the construction can occur in excavations which are laid back to stable slopes. Because

of the sandy soil conditions, we expect that these slopes will be 1 vertical to 1 or 1.5 horizontal. Asmaintaining safe excavation conditions depends heavily on the means, methods, and sequencing ofconstruction, the selection of excavation slopes (pursuant to OSHA and MiOSHA requirements) will bethe responsibility of the contractor.

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Along the south approach, we expect the west side will be either excavated for the proposed hotel or thehotel foundation wall will be in place at the time of construction. However, the existing building on theeast side of the alignment will require excavation support to avoid undermining the foundations.Similarly, the existing TCL&P conduit bank runs within the zone of influence of the excavation. Weunderstand that the City/DDA is considering demolishing the existing building, which could allow opencut of the excavation (with temporary support of the conduit bank). Temporary support of the conduitbank could be completed with cribbing or similar means.

Assuming that demolition of the existing building is not feasible; excavation of the approach will requiretemporary shoring. Shoring options include sheet piling, soldier piling and lagging wall, andtangent/secant pile wall. Though sheet piling represents a relatively low-cost alternative and will providefor some groundwater cut-off, it is our opinion that this option presents significant risks. These risks aredue mainly to vibrations and vibration-induced settlement as sheet piling is typically installed andremoved using vibratory hammers. Vibrations could be detrimental to the adjacent existing building,especially considering its age, condition, and construction. Other options include a soldier pile andlagging wall, which would consist of steel H-piles, concreted in bored holes, with timber laggingspanning between piles and retaining the soil. Though low cost and able to be placed with minimalvibration, care will be necessary to prevent raveling of the sandy soils while excavating and prior toplacing lagging. Though significantly higher in cost, a tangent or secant pile wall will provide support for

the soil and building with little movement or vibrations. This type of wall consists of adjacent oroverlapping holes bored into the soil and filled with concrete.

Planning level costs for these various shoring alternatives are as follows:

Sheet Pile Wall $75,000 - $105,000Soldier Pile and Lagging $85,000 - $110,000Secant Pile Wall $150,000 - $200,000

Based on the estimated costs and the relative risks and merits of the options, assuming that open cut alongthe southeast quadrant of the alignment is not feasible, our opinion is that the soldier pile and lagging wallis the preferred shoring alternative.

Design of shoring will consider potential groundwater levels, earth pressures, and surcharge loads. Thetemporary shoring can/will be incorporated into the final wall.

4.2.10 Snow Melt System (Optional)The snow melt system is conceived to keep the approaches snow-free throughout the winter months. Thesnow melt system will be a hydronic (i.e. boiler water with 40% glycol) system with diameter PEXtubing at 9 on center over the entire length of the tunnel sidewalk and, also, the steps and curved walks atthe north end of the tunnel. The bottom surface of the concrete on the sidewalk, between the concrete andthe compacted sand, will have an insulation layer of concrete barrier foil insulation (e.g. Ultra CBF R-foil which is a bubble wrap sandwiched between foil-faced top and bottom protective layers). The snowmelt system will also have two piping manifolds located under the sidewalk in the tunnel; one at 100-feetand one at 150-feet into the tunnel from the south end. The manifolds will be installed in 30 x 48 x 18deep precast polymer concrete enclosures. These manifolds, fed from the boiler via 3 diameter supply /return mains located under the walkway, distribute the heated hydronic fluid over the distribution networkof under-slab PEX tubing.

One 1,200 MBH gas-fired condensing boiler will be installed in a small equipment building at the northend of the tunnel. That building will also house the boiler hydronic auxiliaries (e.g. air separator,expansion tanks, pumps, boiler & snow melt controls), a unit heater to keep the building warm in winter,and domestic water and gas services.

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Gas for the boiler will come from an active DTE gas main line at the south end of the tunnel on the southside of Garland Street. The project will tie into that line and route an underground gas line to the smallequipment building to connect into the boiler. (Note: According to Ken Lake of DTE Energy the projectwill be responsible for the costs of the gas main tie-in and the boring under Garland Street to get the newgas line from the south side of Garland Street to the south end of the tunnel).

4.2.11 Tunnel Stormwater Drainage

One (1) 36 diameter x 8 deep fiberglass storm water basin with a 3 HP submersible pump will belocated beneath the floor of the tunnel at the north end. This will receive storm water from edge drains onthe side of the tunnel and the approaches.

4.2.12 Tunnel Water Service (Optional)If desired, domestic water service will be routed underground to the equipment building from a city waterutility manhole approx. 100 east of the building on the north side of Grandview Parkway. Domesticwater may also be utilized to feed two (2) freeze-proof wall hydrants at each end of the tunnel for hosewash down of the tunnel.

4.2.13 Tunnel Power DistributionWe plan to add a new 225 amp 120/208V-3PH-4W panel in the new mechanical enclosure and meter it

separately for the project. It will power all loads in the work area, including the snow melt boiler, twopumps, snow melt control panel, unit heater, and a storm sewer lift pump. Six weatherproof receptaclesare planned along the tunnel route for maintenance operations.

4.2.14 Tunnel LightingLED fixtures are planned for down lighting incorporated into fish-shaped overhead panels at the southentrance to the tunnel. Linear LED (rope) fixtures are being considered to outline the five fish panels.Fixture manufacturers and catalog numbers for all areas have not been selected yet.

A new lighting relay panel with integral time clock and photocell will be added to control the lighting onthe project.

Lighting inside the tunnel is planned to be low temperature linear fluorescent or LED fixtures running theentire length of the tunnel along one side at the ceiling and sealed to limit bug access.

The emergency lighting inside the tunnel will be provided by battery backup inside the ambient lightfixtures.

On the north entrance of the tunnel, step lights are planned around the circular retaining walls.

Two spotlight fixtures are planned to highlight the sculpture at the center of the grassy area.

Two fluorescent strip lights are planned to illuminate the inside of the mechanical bunker.

4.2.15 Security Camera System (Optional)Four new CCD CCTV cameras are planned to survey the project area, one at each end of the tunnelpointing inside and one covering each of the two approaches to the tunnel. The cameras will be hardwiredto modems in the mechanical bunker and the images will be available via the internet for monitoringremotely.

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4.2.16 Wind Turbine System (Optional)To produce electricity that will power some of the lighting for the project, a new 1KW wind turbine isplanned on the north side of Grandview with an inverter inside the mechanical bunker.

4.2.17 Maintaining TrafficMaintenance of traffic on Grandview Parkway during construction is a critical and costly part of thisproject. Because traffic volumes are so high (over 27,000 vehicles per day), MDOT has indicated to us

that 4-lanes should be maintained throughout the duration of the tunnel construction. This can beaccomplished by either building a temporary four-lane runaround through the Open Space north of theproject, or by constructing a temporary four-lane bridge a few feet above the project. We examined bothoptions and recommend constructing a four-lane runaround (See drawing for runaround location). Whileboth options have roughly the same cost ($230,000 - $250,000), the runaround option provides space foreasier and faster construction with fewer constructability and quality control issues to work through,ultimately resulting in lower overall construction cost and higher quality workmanship.

We understand that temporary occupancy of the Open Space for maintaining traffic would not requireelectorate approval. We also understand that the extent of temporary construction in the Open Space willbe limited to certain times of year and should be minimized to the extent possible. We will consider part-width construction with input from MDOT during preliminary design to possibly reduce the limits of the

runaround.

4.3 Aesthetic Considerations

This section of the report summarizes the efforts within the Schematic Design phase relative to siteplanning, and primarily site aesthetics. In addition to the established engineering scope, the City and DDAhave indicated the tunnel should be a site element that not only provides a utilitarian function topedestrians, linking Front Street and Downtown, through the Warehouse district, to the Bayfront district;but is designed with an aesthetic that allows it to complement both of these districts that it will serve. Ourobjective in this design phase was to establish the minimum dimensional and spatial guidelines that allowthe tunnel to be a successful series of spaces that relate to their surroundings. Beyond this objective, ourgoal is to provide to the City and DDA an illustration of possibilities that exist once dimensionalstandards are established and we begin to work toward establishing contextual relationships. To this

point, the Schematic Design should be viewed only as a portrait of possibilities within establishedminimum dimensional guidelines. Once we begin to meet with local stakeholders, we will further developthe design to allow it to best respond to the specific district and users.

In meeting the criteria mentioned above, a first step was establishing dimensional minimum standards forthe spaces within the proposed project. These standards were established by recognizing establishedAASHTO standards, ADA accessibility guidelines, and the available space. In addition to these standards,the design team considered spatial relationships between the site and proposed improvements, and theuser. The geometry necessary for the pedestrian underpass presents challenges of spatial perception inorder to create spaces that feel safe and unconfined, comfortable, and interesting. To the limits of the site,these spatial relationships were used to guide dimensional standards and to further refine the design.

Beyond establishing dimensional standards, the design team understands the importance to the City andDDA of sense of place. The project can actually be broken into three separate spaces: the ramp fromGarland Street and the Warehouse District north to the tunnel; the North entry to the Bayfront and openspace; and the tunnel itself.

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4.3.1 South ApproachThe twenty-foot wide South ramp to the tunnel, shown on Sheet C-201, is an extension of an existingpedestrian alley that also figures prominently in the Citys future development plans for the WarehouseDistrict and the proposed Garland Avenue streetscape improvements. The ramp will also border theproposed Hotel Indigo to the west. The design team visited the site to identify the visual and aestheticflavor of the district, and reviewed illustrative graphics from the Streetscape plans, as well as plan andelevation drawings of the proposed hotel. The objective in preparing the schematic design for the

pedestrian ramp was to draw from the existing sense of place of the district, the possible streetscapeimprovements and the proposed hotel to design a pedestrian thoroughfare that is not only functional andaccessible but that emphasizes the context of its surroundings this space has the potential to contributeto further aesthetic development of the warehouse district, so it should be taken very seriously. Weattempted to accomplish this through the use of materials that relate to the district and the proposed hotel,by drawing from the arts content of the district, and by providing opportunities for display of public art.Paving of the ramp is proposed to be concrete with pedestrian-scale detailing. The landings, however, areproposed to be surfaced with cut stone representing an indigenous material. Where the cut stone meetsconcrete paving, we are suggesting a cut stone band engraved with educational or wayfindinginformation. The placement of the cut stone landings is coordinated with the hotel building columns. Thelandings are enlarged in width compared to the ramp, which allows for placement of fishform benches.Behind these benches and between the hotel building columns, we are proposing a decorative trellis

designed to echo the window detailing of the hotel. The trellis would carry ground cover and vinesplanted behind the benches, but would also represent an opportunity to attach artwork. The wall on theeast side of the tunnel would be placed in two terraces to allow for light to reach the space and to provideas open a space as possible. To establish an overhead plane and provide site lighting, we are proposing aleaping fish form ornamental overhead light. The placement of this motif suggests the local heritage ofthe lake and the Boardman River.

During our field inventory and discussions with the City, an electrical ductbank was discovered approx.10 west of the existing building to the east. At this point, it is unclear whether the ductbank will beremoved; however, our initial design for the ramp would require removal and relocation of the ductbank.For this reason, we have prepared an alternate concept for the ramp, shown on Sheet C-301, which leavesthe ductbank in place, maintains the 14 tunnel width, and maintains but simplifies the ramp design in

order to allow narrowing the ramp to 14 width. In this version, the treatment of the west tunnel wall andpavement remains the same, but benches on the east side of the tunnel are eliminated. Because the ductbank location prevents stepping back or terracing of the east retaining wall, that wall now reaches frompavement grade to 2 below existing grade.

Cross sections of each design are shown at the bottom of the respective sheet. While we believe that thedrawings show in plan, profile and cross-section that either ramp option results in an interesting andattractive space, we believe the volume of people using the route, when combined with the narrowerspace, will cause users to move through the space more quickly and possibly with less opportunity tolinger and enjoy the space.

4.3.2 TunnelThe tunnel continues the approach of drawing from the local site context to prepare the schematic design.The materials and forms proposed for the tunnel interior represent what may be found within thewarehouse district. One example is the overhead structure entering the tunnel on either side, a canopy ofstructural steel beams with translucent composite infill to allow light passage and backlighting at night.Once inside the tunnel, a series of stainless steel columns and overhead beams with exposed rivets isplaced within, appearing as a structural element. The fact that the tunnel is the most confined of spaceswithin the sequence suggests to us that the space within needs significant embellishment to ensure it is aninteresting space and not merely a confining space that users prefer to enter and exit as quickly aspossible. In order to achieve this, we drew from the Citys desire to incorporate educational opportunities.The west wall of the tunnel is proposed to be faced with backlit glass block, with the suggestion that thewall can be used for artwork. Another suggestion for treatment of the glass block wall is to etch the

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profile of Grand Traverse Bay and the profile of the landform above it into the block itself. Glass blocksbelow the etched waterline could be filled with masses of suspended small medallions that could playoff the light to represent schools of fish. The tunnel floor is proposed to receive tile, which could beetched to provide educational and wayfinding information, possibly corresponding with the etched profileof the bay and landforms. Finally, the tunnel ceiling is proposed to be perforated and backlit in a mannerresembling a starry night sky. Linear fluorescent or LED lighting on one side of the tunnel ceiling willsupplement the ceiling lighting.

4.3.3 Open SpaceThe North Entry Plaza, shown on Sheets C-202 and C-302, is where the Warehouse district meets theBayfront district. This district has the completely different spatial relationships of the existing park openspace. Thus, the space should respect the established Bayfront context and its spatial relationships.However, when approaching and entering the space, it should also make a visual connection to theWarehouse District that it serves. Our objective in developing the space was to bring the user to gradelevel with as open, universally accessible, and unconfined a route as possible; to mark starting points forthe different districts, and to respect the open space and lake views by minimizing disturbance of the openspace and obstruction of the bay. As in the Schematic Design of the south ramp and tunnel, the proposedimprovements shown for the North Entry should be viewed as a proposed establishment of spaces and amenu of possibilities in terms of site features and finishes that require the input of the City, DDA and

local stakeholders.

Included in our plans are two design options for the North Entry Plaza. The initial option, shown on SheetC-202, brings users through the end of the tunnel and around a central island bordered with a seat heightretaining wall. The center island includes a terrace facing the tunnel, proposed to be faced with brickmatching the hotel. The terrace and island itself are shown planted with dune grasses and low evergreensto resemble native dune vegetation. Within the island, a small sculpture pool is located for placement androtation of sculpture work. Pedestrians can follow the concrete and cut stone ramps and landings aroundeither side of this island to walks taking them to the open space or marina. The sidewalk leading to themarina also passes through the central plaza on its way up a set of proposed stairs and to the GrandviewParkway, providing a strong sightline from above. The plaza reaches grade as the two walks borderingthe center island come together to form a circle. In this area, pavement is widened, bollard lights and

Mast and Yard Arm poles carrying banners, and benches are proposed, and the space is enclosed withmore low, native vegetation in order to emphasize a sense of arrival.

Upon presenting the concept for the North Entry Plaza shown on Sheet C-202, we received feedback thata lower-impact solution may be desired. We have prepared an alternate design solution for this space thatreduces the impact, brings users centrally through the space as opposed to around a landscape island, andspreads grading and earthwork in a more gradual manner toward the bay and open space. This option isshown on Sheet C-302. The retaining wall framing the tunnel entry is now profiled to resemble a duneform and planted foreground and background with dune grasses and low evergreen vegetation. Sculpturebases are suggested in front of the dune-form wall within the drifts of dune grass. Sense of arrival ismaintained with a smaller central plaza that retains the benches, Mast and Yard Arms, and lighting of theinitial option. While the ramps in this option extend further and more gradually into the existing openspace, the overall impact of the improvements will be less dramatic.

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4.4 Construction Budget

The Engineers Opinion of Probable Construction Costs is summarized in the table below. The table isorganized to allow comparisons to the Traverse City Bayfront 2010 budgets and to identify optionalversus required work. Also note that the items covered in our estimates are coordinated with Greenan andAssociates, LLCs Summary Report of Streetscape Improvements dated April 26, 2011, to avoid repeated

budget items. A more detailed breakdown is included in Appendix B of this report.

Engineers Opinion of Probable Construction Costs - Summary Table

Item *Tunnel**SouthApproach

***OpenSpace

****OptionalWork Totals

General $434,600 $183,000 $117,600 $0 $735,200

Maintaining Traffic $235,800 $0 $0 $0 $235,800

Tunnel AestheticTreatments

$0$0 $0 $168,800 $168,800

Landscaping /Amenities $14,800 $0 $0 $287,200$302,000

Snow Melt System $0 $0 $0 $165,000 $165,000

General Mechanical $15,000 $0 $0 $19,400 $34,400

Electrical / Lighting $26,800 $0 $0 $32,000 $58,800

TCL&P Relocation $0 $0 $0 $400,000 $400,000

10% Contingency $72,700 $18,300 $11,760 $107,240 $210,000

Totals $799,700 $201,300 $129,360 $1,179,640 $2,310,000

* Tunnel consists of work between and including the tunnel headwalls.** South Approach consists of work south of the tunnel headwalls and is referred to as South Ramp toWarehouse District in the Drawings.*** Open Space consists of work north of the tunnel headwall and is referred to as Bayfront Entrancein the Drawings.**** See Appendix B for a detailed breakdown of Optional Work.

Notes:1. MDOT costs are unknown and therefore not included at this time. MDOT costs will include

permanent use of right-of-way, agreements, MDOT reviews and a construction permit.2. Design, construction and environmental engineering costs are not included in the Engineers

Opinion of Probable Construction Costs.

3. Maintenance and operation costs of the project are not included in the Engineers Opinion ofProbable Construction Costs at this time.

4. Options 1 and 2 for Open Space work are estimated to have roughly the same cost, so thenumbers indicated in the table are for either option.

5. Actual construction costs may vary significantly depending upon the timing of construction,market conditions and other factors beyond our control.

We understand that the current budget for this project is about $1.1 million. We will work with theCity/DDA to assist in making project scope decisions.

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5.0 RECOMMENDATIONS

We recommend proceeding with preliminary design consistent with the design element recommendationsdescribed above. However, the following items require special consideration and input from theCity/DDA:

A decision is needed regarding option with or without TCL&P electrical relocation. Resolution of schematic design estimate versus current budget. Decisions regardingrecommended optional items are needed.

NDG will actively work with the City/DDA to resolve these and other issues as required to successfullycomplete this project.

We appreciate the opportunity to be of service. If you have any questions concerning this report orrequire additional information, please do not hesitate to contact us.

Respectfully submitted,

LUCAS C. PORATH, P.E.Vice President

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APPENDIX A

SCHEMATIC DESIGN PLANS

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CITY OF TRAVERSE CITY

GRANDVIEW PARKWAY (US-31)PEDSTRIAN TUNNEL

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APPENDIX B

SCHEMATIC DESIGN ESTIMATE

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Filchematic Design Estimate Estimate Date: 7

ty of Traverse City/DDA NDG Project No. randview Parkway Pedestrian Tunnel

averse City, Michigan

Lucas Porath, P.E.

Northwest Design Group, Inc.Petoskey, Michigan

Unit Unit Price Qty Amount Qty Amount Qty Amount Qty Amou

Syd $4.00 335 $1,340.00 0 $0.00 0 $0.00 0 $0.00Ft $5.00 120 $600.00 0 $0.00 0 $0.00 0 $0.00

Cyd $4.00 0 $0.00 0 $0.00 750 $3,000.00 0 $0.00

Cyd $8.00 1,780 $14,240.00 0 $0.00 0 $0.00 0 $0.00Cyd $12.00 755 $9,060.00 0 $0.00 0 $0.00 0 $0.00Cyd $35.00 165 $5,775.00 0 $0.00 0 $0.00 0 $0.00Ft $2,500.00 88 $220,000.00 0 $0.00 0 $0.00 0 $0.00Sft $6.75 10,225 $69,018.75 0 $0.00 0 $0.00 0 $0.00

Ft $5.00 390 $1,950.00 0 $0.00 0 $0.00 0 $0.00LS $110,000.00 0 $0.00 1 $110,000.00 0 $0.00 0 $0.00Cyd $425.00 30 $12,750.00 120 $51,000.00 150 $63,750.00 0 $0.00Lbs $1.00 3,700 $3,700.00 12,950 $12,950.00 18,550 $18,550.00 0 $0.00Sft $4.50 1,160 $5,221.60 2,000 $8,997.75 3,290 $14,802.75 0 $0.00

Cyd $800.00 0 $0.00 0 $0.00 10 $8,000.00 0 $0.00Ft $90.00 465 $41,850.00 0 $0.00 0 $0.00 0 $0.00Ft $95.00 0 $0.00 0 $0.00 100 $9,500.00 0 $0.00Ft $100.00 80 $8,000.00 0 $0.00 0 $0.00 0 $0.00

Ton $80.00 15 $1,200.00 0 $0.00 0 $0.00 0 $0.00

Syd $75.00 335 $25,125.00 0 $0.00 0 $0.00 0 $0.00

Syd $5.50 335 $1,842.50 0 $0.00 0 $0.00 0 $0.00Syd $4.00 90 $360.00 0 $0.00 0 $0.00 0 $0.00Ft $30.00 250 $7,500.00 0 $0.00 0 $0.00 0 $0.00

Ft $150.00 34 $5,100.00 0 $0.00 0 $0.00 0 $0.00SUBTOTALS: $434,632.85 $182,947.75 $117,602.75 $0.00

Ft $7.00 970 $6,790.00 0 $0.00 0 $0.00 0 $0.00Cyd $5.00 1,070 $5,350.00 0 $0.00 0 $0.00 0 $0.00

Cyd $11.00 1,470 $16,170.00 0 $0.00 0 $0.00 0 $0.00Syd $6.00 4,300 $25,800.00 0 $0.00 0 $0.00 0 $0.00Ton $70.00 925 $64,750.00 0 $0.00 0 $0.00 0 $0.00Ft $0.30 7,000 $2,100.00 0 $0.00 0 $0.00 0 $0.00LS $10,000.00 1 $10,000.00 0 $0.00 0 $0.00 0 $0.00

Cyd $5.00 2,900 $14,500.00 0 $0.00 0 $0.00 0 $0.00Ft $18.00 970 $17,460.00 0 $0.00 0 $0.00 0 $0.00

Syd $5.25 1,960 $10,290.00 0 $0.00 0 $0.00 0 $0.00Ton $80.00 305 $24,400.00 0 $0.00 0 $0.00 0 $0.00Ea $1,000.00 5 $5,000.00 0 $0.00 0 $0.00 0 $0.00

Syd $4.00 8,300 $33,200.00 0 $0.00 0 $0.00 0 $0.00LS UNKNOWN

SUBTOTALS: $235,810.00 $0.00 $0.00 $0.00

Sft $22.00 0 $0.00 0 $0.00 0 $0.00 1,250 $27,500

Sft $30.00 0 $0.00 0 $0.00 0 $0.00 1,600 $48,000Sft $25.00 0 $0.00 0 $0.00 0 $0.00 1,250 $31,250Sft $20.00 0 $0.00 0 $0.00 0 $0.00 3,100 $62,000

SUBTOTALS: $0.00 $0.00 $0.00 $168,750

Ft $65.00 0 $0.00 0 $0.00 0 $0.00 30 $1,950.0Ea $2,500.00 0 $0.00 0 $0.00 0 $0.00 11 $27,500Ea $1,500.00 0 $0.00 0 $0.00 0 $0.00 5 $7,500.0LS $5,000.00 0 $0.00 0 $0.00 0 $0.00 1 $5,000.0

Ea $5,500.00 0 $0.00 0 $0.00 0 $0.00 3 $16,500Ea $30,000.00 0 $0.00 0 $0.00 0 $0.00 2 $60,000Ea $15,000.00 0 $0.00 0 $0.00 0 $0.00 5 $75,000Ft $35.00 0 $0.00 0 $0.00 0 $0.00 135 $4,725.0

Syd $5.00 550 $2,750.00 0 $0.00 0 $0.00 0 $0.00

LS $12,000.00 1 $12,000.00 0 $0.00 0 $0.00 0 $0.00Sft $10.00 0 $0.00 0 $0.00 0 $0.00 6,000 $60,000LS $25,000.00 0 $0.00 0 $0.00 0 $0.00 1 $25,000LS $4,000.00 0 $0.00 0 $0.00 0 $0.00 1 $4,000.0

SUBTOTALS: $14,750.00 $0.00 $0.00 $287,175

Ea $3,000.00 0 $0.00 0 $0.00 0 $0.00 1 $3,000.0Ft $40.00 0 $0.00 0 $0.00 0 $0.00 100 $4,000.0LS $200.00 0 $0.00 0 $0.00 0 $0.00 2 $400.0

LS $165,000.00 0 $0.00 0 $0.00 0 $0.00 1 $165,000Sft $200.00 0 $0.00 0 $0.00 0 $0.00 60 $12,000LS $15,000.00 1 $15,000.00 0 $0.00 0 $0.00 0 $0.00

SUBTOTALS: $15,000.00 $0.00 $0.00 $184,400

Ea $3,700.00 1 $3,700.00 0 $0.00 0 $0.00 0 $0.00

Ft $25.05 100 $2,505.00 0 $0.00 0 $0.00 0 $0.00Ft $6.92 1,500 $10,380.00 0 $0.00 0 $0.00 0 $0.00Ea $251.00 2 $502.00 0 $0.00 0 $0.00 0 $0.00Ea $1,375.00 1 $1,375.00 0 $0.00 0 $0.00 0 $0.00Ea $45.50 6 $273.00 0 $0.00 0 $0.00 0 $0.00

Ea $170.00 0 $0.00 0 $0.00 0 $0.00 4 $680.0Ft $30.00 0 $0.00 0 $0.00 0 $0.00 150 $4,500.0Ea $1,500.00 1 $1,500.00 0 $0.00 0 $0.00 0 $0.00Ft $50.00 80 $4,000.00 0 $0.00 0 $0.00 0 $0.00

Ea $100.00 26 $2,600.00 0 $0.00 0 $0.00 0 $0.00Ea $150.00 0 $0.00 0 $0.00 0 $0.00 2 $300.0Ea $4,500.00 0 $0.00 0 $0.00 0 $0.00 4 $18,000Ea $8,500.00 0 $0.00 0 $0.00 0 $0.00 1 $8,500.0LS $400,000.00 0 $0.00 0 $0.00 0 $0.00 1 $400,000

SUBTOTALS: $26,835.00 $0.00 $0.00 $431,980

TOTAL ALL CATEGORIES: $727,027.85 $182,947.75 $117,602.75 $1,072,30

CONTINGENCY (10%): $72,702.78 $18,294.78 $11,760.28 $107,230

TOTAL INCLUDING CONTINGENCY: $799,730.63 $201,242.53 $129,363.03 $1,179,53

PROJECT TOTAL: $2,09

Optional WorkTunnel South Approach Open Space

omestic Water Piping

xcavation Shoring

I-FI Cameras WP FixedKW Wind Turbine

anch Wiring 30 Circuits at 50 Feet/Circuit

ump Connections and Startersorm Water Sump StarterP Receptacles

ED Downlights on Fish PanelsED Rope Lighting on Fish Panels

omestic Water tie-in w / meter

culpture Lighting

echanical Buildingnow Melt System

ghting Relay PanelED Tunnel Lightingep Lights

estoration

CL&P Electrical Relocation

eeze-proof Wall Hydrants

ormwater Basin & Pump, Controls, etc.

ectrical0/208V-3PH-4W Panel, 30 ckt0 Amp Feeder for Panel from Pwr Co

ndscaping, Planting Beds

te Furnishing, Trash Recepticlete Furnishings, Signage

ndscaping, Shrubsndscaping, Trees

odding

ggregate Base, 6 inch

te Furnishings, Decorative Lighting, Ramp Landing

echanical

Description

te Furnishing, Bench

te Furnishings, Decorative Entry Arch

esthetics Treatment, Retaining Walls

dewalk, Conc, 6 inch

onc Curb and Gutter

eps, Conc

MA

ggregate Base, 8 inch

xcavation, Earthxcavation, Fdnackfill, Structure, CIP

ulv Bedding, Box Culv

avt, Remurb, Rem

ee Removal and Replacement

emp Pavement Markings

xcavation, Earth (Remove Temp Runaround)

urb, Remxcavation, Earth (Construct Temp Runaround)ubbase, CIPggregate Base, 8 inch

MA (Temp Runaround)

estoration

unnel & Approach Waterproofingunnel Edge Drain

oncrete, Grade S2 (Retaining Walls, Etc.)einforcement, Steel, Epoxy Coated

oncrete Pavment

eneral

pe Railing for Stepsrnamental Guardrail

pe Railing

unnel Structure, 14 foot by 9 foot

aintaining Traffic

orm Sewerench Drain

ggregate Base, 6 inch (Path and Parking Lot)MA (Path and Parking Lot)

emp Signs, Maintaining Traffic

esthetics Treatment, Tunnel Ceiling

te Furnishings, Decorative Trellis

creening Fence

te Furnishings, Mast Arm with Banner

Engineer's Opinion of Probable Construction Costs

te Landscaping and Amenities

DOT Fees

unnel Aesthetic Treatmentsesthetics Treatment, Tunnel Floor

esthetics Treatment, Tunnel Wall

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APPENDIX C:

MDOT PERMIT APPLICATION CORRESPONDANCE

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