SOW_-_Tanawha_Bridge_Repair.pdf

Statement of Work Tanawha Bridge Emergency Repair Blue Ridge Parkway

September 21, 2018

STATEMENT OF

WORK

TANAWHA BRIDGE EMERGENCY REPAIR

Watauga County, North Carolina

PART 1 – GENERAL

1‐1 DESCRIPTION OF WORK

A. The Tanawha Trail, stretching 13.5 miles from Julian Price Park to Beacon Heights, parallels the Blue Ridge Parkway on Grandfather Mountain in North Carolina. Tanawha, the Cherokee work for fabulous hawk or eagle, is an appropriate name for this trail that offers hikers spectacular views of distant mountains. Completed in 1993, the Tanawha Trail, like the final section of the parkway it mirrors, is unique in construction. The trail traverses a fragile and ancient ecosystem and leads hikers through a surprising range of biological and geological terrains. Some sections tunnel through thickets of laurel and rhododendron. Others dip down into remote hardwood coves and then ascend into evergreen glens. Boulder fields and cascading streams punctuate the landscape. Sections above the Viaduct and along Rough Ridge are strenuous, but overall the trail is an easy to moderate walk.

The many accesses from the parkway let hikers choose as long a section as they like.

The foot bridge crossing over Boone Fork Creek was closed to all use in June 2018. The north pier has become severely eroded from significant rainfall. The intent of this project is to restore the integrity of the north pier.

B. This Statement of Work (SOW) consists of:

1. Constructing reinforced concrete repair area

2. Placing mortared river rock rip rap

3. Constructing a swale‐berm

4. Restore and dress disturbed areas as needed

C. Attachments:

1. Project Plans

2. CM‐16 Transmittals Form (Submittals)

3. BLUE RIDGE PARKWAY LOAD LIMITS

4. Existing Condition Photos

1‐2 LOCATION AND ACCESS

A. Job Site: The bridge site is accessible from the Boone Fork Parking Area on the Blue Ridge

Parkway near Milepost 299.5 in Watauga County, North Carolina. The bridge is located approximately 1/2 mile up the Tanawha Trail from the parking area.

B. Access

1. Access to the work site for commercial vehicles shall be from Holloway Mountain Road then south to the Boone Fork Parking Area.

2. The maximum permitted load limits for Parkway roads accessing the work site are described in attachment BLUE RIDGE PARKWAY LOAD LIMITS.

3. Special consideration may be made by the Contracting Officer’s Representative (COR) in consultation with the park engineer for overweight and oversize loads. Special permits, times and traffic control may be required for heavy/wide loads.

4. All damage shall be repaired to the Government’s specification by those who cause it and at no cost to the Government. Return the area to the condition existing prior to any work.

1‐5 WORK CONDITIONS AND LIMITATIONS

A. Facility Use

1. This section of Parkway motor road opens to visitors year‐round, 24‐hours a day weather permitting. Visitation is highest during summer months and especially leaf viewing season (typically October).

2. The Tanawha Trail is highly used trail be a variety of visitors. The NPS has officially closed this section of trail; however, visitors may still be in the vicinity of the work and parking area.

3.

B. Field Verification

1. The measurements and quantities specified are estimated and provided for information only.

The Contractor shall verify all dimensions and conditions affecting the work.

2. The Contractor shall notify the Contracting Officer’s Representative (COR) of any errors or omissions as soon as realized.

C. Park‐Specific Conditions and Limitations

1. The Blue Ridge Parkway is wholly located along the ridges of the Appalachian Mountain range in parts of Virginia and North Carolina. The following conditions may be applicable to work sites inside Parkway boundaries:

a. WEATHER‐ Sudden and dramatic changes in climate conditions are common. The Contractor must be prepared to alter work plans and provide protection for workers and equipment.

b. CLOSURES‐ Parkway officials may close portions of the Parkway at any time to protect visitors from hazardous conditions or to implement official duties of the Parkway.

c. REMOTENESS‐ Many portions of the Parkway are of extreme distance to typical services available in developed areas, including cellular, food, fuel, and emergency services. The Contractor must arrange and account for appropriate precautions and plans prior to bid submission.

d. RESOURCES‐ As a unit of the National Park System, the Blue Ridge Parkway is tasked to preserve unimpaired its natural and cultural resources and values. The Contractor must make every effort to ensure no impacts are made deleterious to these resources. It is expected that the project site and access areas will be minimally impacted only as absolutely necessary for the performance of the SOW requirements. Mitigations approved by the COR will be taken to restore pre‐existing conditions.

e. ROCK‐ The presence of various forms of rock is ubiquitous. The Parkway does not maintain data for construction purposes on the location or type of rock to be encountered by excavation or drilling activities. The contractor must verify and account for the extent, nature and impact to work activities of rock within the project site prior bid submission.

f. INVASIVE EXOTICS‐ To reduce the chance that harmful, non‐native plants or organisms will be transported from off‐parkway locations to the work site, the contractor, prior to entering the parkway, must clean all soils, roots, seeds, and other sources of plant parts and pathogens from any equipment used for the application of grasses and all heavy equipment, such as dump trucks, front end loader, and graders, which have previously been operating off the park.

g. WILDLIFE‐ All wildlife is protected within the park boundaries, and some species, which occur within the park, receive special State and Federal protection due to their rare, threatened or endangered status. Very few wildlife species present any danger to persons working within the park. Even species which have the potential to do harm to persons, can usually be avoided. Unless wildlife is presenting an immediate threat to persons, harassment or destruction of wildlife is prohibited.

2. Project‐specific environmental compliance mitigations

a. All materials and equipment shall be transported to the work site via the Tanawha Trail from the Boone Fork Parking Area. No vehicles, other than motorized wheelbarrow, will be permitted on the trail. All materials, vehicles and equipment shall be staged within the paved area of the Boone Fork Parking Area.

b. Activity related to this project shall not occur within Trout Moratorium dates of October 15‐April 15.

c. Erosion control matting that incorporates plastic mesh and/or plastic twine shall not be used in this project.

d. Erosion and sediment control designs shall comply with the requirements set forth in Design Standards in Sensitive Watersheds.(15A NCAC 02H .0501 and .0502)

e. All care should be taken to ensure that all materials are kept from being discharged into the water.

f. If concrete is used during construction, then all necessary measures shall be taken to prevent direct contact between uncured or curing concrete and waters of the state. Water that inadvertently contacts uncured concrete shall not be discharged to waters of the state.

g. Erosion control methods shall be used to prevent silt‐laden water from entering the stream. These may include, but are not limited to, silt fencing, filter fabric, excelsior or fumigated straw filter logs, temporary sediment ponds, check dams of pea gravel‐filled burlap bags or other material, and/or immediate mulching of exposed areas. In order to prevent import of non‐native plants, straw bales or non‐fumigated products shall not be permitted. This measure is designed to keep fine and coarse sediments from reaching flowing waters where they can be transported downstream and may affect spawning gravels, substrate embeddedness, pool frequency/quality and the development of large pools. Silt protection structures should be inspected and cleaned out periodically.

h. Excavation shall consist solely of accumulated sediment and should not alter the natural bed and banks of the channel.

1‐6 QUALITY CONTROL

A. It is the responsibility of the Contractor to develop and implement a construction quality process to ensure work conforms to the requirements of the contract, work is in accordance with manufacturer specifications, and work is performed to modern, typical industry standards for this type of work.

B. Perform quality control inspection, documentation and process control sampling and testing as required by applicable standards.

C. All materials and methods used shall meet or exceed the current local, state, and federal codes, standards, and regulations applicable to this project.

D. The COR will perform on‐site inspections to insure conformance to this contract. The Government reserves the right to perform any testing it sees fit to insure a satisfactory product is delivered. Any non‐conforming work will be removed and replaced at no cost to the Government.

1‐7 REFERENCE STANDARDS:

Any necessary standards are included in this SOW.

1‐8 SUBMITTALS AND PROCEDURES

A. General

1. Refer to attached CM‐16 Transmittal Form for required submittal items. Contractor is responsible for additional submittals that may be required. Electronic forms are available.

2. Unless otherwise instructed by the CO, send construction material and other items requiring approval to the CO and COR. Provide one (1) electronic copy of each submittal unless otherwise specified. Forward related materials as a package. Reference the SOW section number on each submittal. Allow 14 days for review and approval.

3. The CO or COR will indicate in writing the approval or disapproval of each submittal, the reason for any disapproval, and any resubmission requirements. One (1) of each approved submittal will be stamped and returned to the Contractor unless otherwise requested.

4. Until the Contractor receives approval from the CO or COR, no construction material or other items requiring the CO or COR’s approval may be ordered, delivered, or incorporated into the project work.

5. There will be no waiver of any required submittal unless authorized by the CO or COR.

The CO may request submittals other than those specified in this document.

6. Submit as a package all required items under each submittal item.

B. Submittals: Work Plans

1. Project Schedule

a. Contractor shall submit a construction schedule outlining each phase of the work along with a written narrative of the activities displayed in the schedule.

b. See FAR 52.236‐15 Schedules for Construction Contracts.

C. Submittals: Materials

1. Concrete shall have a minimum 4,000psi compressive strength.

2. Rebar shall be deformed, size No.5 and Grade 60.

3. Mortar mix shall be Type S.

4. Rip rap shall match characteristics of surrounding river rock. Stones shall be 12in to 18in in dimension.

PART 2 – WORK

REQUIREMENTS 2‐1

GENERAL

A. The Contractor is responsible for investigating site conditions in the vicinity of the required work.

Notify the COR as soon as possible of any discrepancies between the SOW and field conditions.

B. Any excess material and debris shall be disposed of properly at acceptable facilities on non‐Federal land.

2‐2 TRAFFIC AND PEDESTRIAN CONTROL

A. Traffic control, if necessary, shall be in accordance with the Manual on Uniform Traffic Control Devices (MUTCD).

B. The Contractor is responsible for providing, placing, and maintaining additional pedestrian controls to include trained flaggers around the project. The details of which shall be included within the Safety Plan.

2‐3 EXECUTION

A. General

1. Reference attached “Existing Conditions” photo log.

2. Below is a general approach to complete each of the work items. The steps below are not intended to control the Contractor’s means and methods.

3. The work of this project shall be performed during the dry season which is typically fall. The contractor shall be sufficiently prepared to protect the river from the work and the work from the river until the project is complete.

B. Mobilization and Demobilization

1. Confine staging and parking for vehicles, equipment, and materials to the Boone Fork Parking area.

2. Protect from damage all resources not included in the project work. Restore or repair any damaged resources to COR acceptance.

3. The Contractor shall provide for methods to appropriately secure the work site including equipment and materials and is ultimately responsible for the project site through the duration of the project.

4. Access site only by methods described in SOW Section 1‐2.

5. Provide, install, and maintain appropriate erosion and sediment controls, temporary traffic devices, and additional necessary pedestrian control devices prior to work beginning.

C. Repair eroded area

1. Provide concrete and rebar to meet SOW Section 1‐8.C.

2. Do not remove material directly below the bridge pier footing.

3. Remove by hand loose rocks where the repair area concrete will contact the river bed and river bank on each side of the pier. Insure river bed material below the repair area concrete is solid and competent.

4. Install a rebar cage to meet the Project Plans.

5. Erect formwork to meet the dimensions of the Project Plans.

6. Formwork shall be sufficiently secured to prevent failure and depositing of fresh concrete into flowing water.

7. Key new concrete into river bed and river bank.

8. Mix and place concrete in accordance with manufacturer guidelines.

9. Sufficiently vibrate the concrete placement throughout the repair area

10. Provide keyed area for mortared rip rap.

11. Finished concrete shall be reasonably smooth and free of holes.

D. Mortared rip rap

1. Provide mortar and rip rap stone to meet SOW Section 1‐8.C

2. Mix and place mortar in accordance with manufacturer guidelines.

3. Key rip rap into the river bank.

4. Finished work shall have to the appearance of dry laid stone.

5. Backfill around the top of the rip rap to prevent runoff from getting behind the stone.

E. Swale‐Berm construction

1. Determine the best location and route for the work.

2. Insure swale outlets at hardened area to handle runoff.

3. Construct by hand the swale along the determined route and to the dimensions in the Project

Plans.

4. Compact swale bottom and remove roots and rocks to insure swale will be unobstructed and free flowing.

5. Roughen the existing surface where the berm will be constructed.

6. Construct by hand the berm along the determined route and to the dimensions in the Project

Plans.

7. Sufficiently compact berm to insure it will remain firm and stable.

8. Restore and dress disturbed areas as needed.

2‐4 CLEAN UP

A. Routine Cleanup: Keep project site neat, orderly and in safe condition at all times. Provide enough refuse containers for collecting construction debris. Pick up construction debris daily to prevent blowing and scattering. Keep volatile wastes in covered containers. Unless otherwise specified, all removed material becomes the property of the contractor and shall be disposed of outside of the park in accordance to local, state and county regulations. Food trash and debris shall be disposed of in the proper bear‐proof trash containers. Trash containers may not be available throughout the duration of the project so the Contractor shall dispose of food trash and debris off‐site at the end of each work day.

B. Final Cleanup: Remove all tools, equipment, surplus materials and rubbish from the site upon completion of the work. Restore, refinish or repair surfaces of existing resources that are marred, scratched or damaged due to work of this contract, to match the original condition. Remove any grease, dirt, asphalt, stains or foreign material from the finished surfaces. At time of the final inspection, project site shall be thoroughly clean and ready for use.

2‐5 CLOSEOUT

A. Closeout Submittals: Upon completion of the work, the Contractor shall provide any final submittals called for in Section 1‐8.

B. Substantial Completion and Final Inspection: Submit written certification that project, or designated portion of the project, is substantially complete, and request in writing a final inspection. The NPS or designated representative will make an inspection within 10 days of receipt of request. When the NPS determines the work is substantially complete, a Letter of Substantial Completion will be issued along with a list of any deficiencies to be corrected before final acceptance. If the NPS determines the work is not substantially complete, the Contractor will be notified in writing, stating the reasons.

After completing the work, Contractor shall resubmit certification and request a new final inspection.

END OF

STATEMENT