RFQ_32110-19125_SWC_191_Slope_Stabilization_ProForma_Release_2.pdf

CONTRACT

BETWEEN THE STATE OF TENNESSEE,

DEPARTMENT OF GENERAL SERVICES

CENTRAL PROCUREMENT OFFICE

AND

CONTRACTOR NAME

This Contract, by and between the State of Tennessee, Department of General Services, Central Procurement Office (“State”) and Contractor Legal Entity Name (“Contractor”), is for the provision of Statewide Contract (SWC) 191 Slope Stabilization Services as further defined in the "SCOPE." State and Contractor may be referred to individually as a “Party” or collectively as the “Parties” to this Contract.

The Contractor is a/an Individual, For-Profit Corporation, Non-Profit Corporation, Special Purpose Corporation Or Association, Partnership, Joint Venture, Or Limited Liability Company.

Contractor Place of Incorporation or Organization: Location Contractor Edison Registration ID # Number

A. SCOPE:

A.1. The Contractor shall provide all goods or services and deliverables as required, described, and detailed below and shall meet all service and delivery timelines as specified by this Contract.

A.2. Definitions. For purposes of this Contract, definitions shall be as follows and as set forth in the Contract:

a. “ACI” means the American Concrete Institute.

b. “AASHTO” means the American Association of State Highway and Transportation

Officials.

c. “ASTM” means the American Society for Testing and Materials.

d. “Engineer” means a registered professional engineer licensed in the State of Tennessee, who is knowledgeable in the design and implementation of slope stabilization and related work.

A.3. Scope. The Contractor shall provide slope stabilization and other services as specified in this contract below. The State or Authorized User shall identify locations of all work to be performed as specified herein. The Contractor shall provide labor, equipment, supervision, and to provide “on-call” services as needed for emergency landslide repairs. The Contractor shall provide services under one or more of the following groups:

1) Group One: Soil Nailing

2) Group Two: Horizontal Drains

3) Group Three: Railroad Rails and Cribbing

4) Group Four: Rockfall Mitigation

5 ) Group Five: Compaction Grouting

The Contractor shall be responsible for cleanup. The Contractor shall ensure that the work area is clean of debris, unused material, etc. at the end of each day to ensure safety. The Contractor shall clean up and haul away debris when work is completed.

A.4. Special Provisions, Standards, and Specifications.

a. Contractors shall comply with the special provisions provided in Attachment 2

b. Contractors shall comply with the industry standards and specifications outlined throughout this Contract, including but not limited to the standards and specifications promulgated by the American Society for Testing and Materials (ASTM), American Concrete Institute (ACI), and the American Association of State Highway and Transportation Officials (AASHTO). Contractors shall remain in compliance with any updates to these standards or specifications throughout the Term of this Contract.

A.5. Contractor Award of Non-Emergency Jobs - Each group may have an A, B, and C Contractor. A through C Contractor shall be determined based on the first (A), second (B), and third (C) highest score each Contractor receives on their Request for Qualifications in each individual group. For each Group, Contractor A shall be given the first opportunity to perform all non-emergency jobs. Jobs involving a mix of work from more than one Group (e.g. Group One Soil Nailing and Group Two Horizontal Drains) may be quoted among all Contractors awarded within the applicable Groups and award of the job shall be made to the Contractor who is able to complete the job in the most time-efficient manner as defined by the Authorized User.

a. Estimates shall be provided free of charge to the Authorized User. The Contractor shall not charge for any time on-site or travel costs associated with putting together and providing an estimate.

b. Estimates shall be broken down according to the item numbers on the contract.

c. The repair cost shall not exceed the amount estimated without written justification from the Contractor and prior written approval from the Authorized User.

d. Estimates shall be monitored by the Authorized User for accuracy.

e. The Contractor shall perform the services as described in the estimate, upon request from the Authorized User.

f. Estimates shall be provided to the Authorized User within three (3) business days after the initial request is made by the Authorized User unless otherwise specified by the Authorized User.

g. In the event that Contractor A is unreachable after twenty-four (24) hours of initial contact or unable to perform the work for any reason including but not limited to time constraints, the Authorized User shall move to Contractor B. The same process shall apply if Contractor B is unable to perform the work and Authorized Users shall move to Contractor C. If Contractor C is unable to perform the work, the Authorized User should contact the Contract Administrator and solicit work from a non-Contract supplier upon approval from the Central Procurement Office (CPO).

A.6. Contractor Award of Emergency Jobs.

a. Authorized Users shall use “constant compete” based on time, when dealing with what the Authorized User determines are emergency situations. The Authorized User shall send the A, B, and C Contractors a detailed scope of the emergency job. The Contractors shall respond back with the date they can start the job, as well as the estimated completion date. The job shall be awarded to the Contractor who is able to complete the job in the most time efficient manner as defined by the Authorized User.

b. In order for a Contractor to be considered for award of an emergency job, the Contractor must respond with its timeline within three (3) hours of initial contact by the Authorized User.

c. The Authorized User has the sole discretion to determine the job as an emergency.

The Authorized User shall indicate that the job is an emergency when requesting service for the job.

A.7. Site Visits.

a. The Contractor shall be called out for a site visit in company with the Authorized

User’s Geotechnical or Maintenance personnel prior to issuance of a Purchase Order. The Contractor shall schedule and conduct the site visit within forty-eight (48) hours following notification by Authorized User personnel. The purpose of the site visit shall be for the Contractor to evaluate and prepare an estimate of the materials and services needed to repair the site to the Engineer’s specifications. The Contractor shall provide a detailed written estimate of materials and services needed to repair the site to the Authorized User’s specifications within forty-eight (48) hours following the site visit. The Contractor is responsible for the accuracy of their measurements.

Any necessary subsurface exploration, site survey, and slope stability modeling to prepare the estimate is the responsibility of the Contractor. If it is determined that a subsurface exploration is required, the time frame required to conduct the subsurface and exploration and provide a repair estimate shall be jointly agreed upon by the Authorized User and the Contractor.

b. Emergency site visit: The Contractor shall schedule a site visit within twenty-four (24) hours following notification by Authorized User personnel in the event of an emergency, as determined by the Authorized User. The Contractor shall follow the same procedures as described in section A.7.a. concerning the estimate and specifications.

c. All written estimates for Group One, Soil Nailing shall contain a warranty statement guaranteeing the full roadway stability of the repaired section for a period of seven (7) years, and that any necessary repairs shall be made in the timeframe specified by the Authorized User at no cost to the Authorized User. This warranty statement shall be jointly endorsed by the Contractor and the Contractor’s Engineer.

A.8. Engineering Plans. Following review of the repair estimate and issuance of a purchase order, the Contractor shall provide all necessary engineering plans and details required to successfully repair landslides for review and approval by either the TDOT Geotechnical Office or other applicable Authorized User.

A.9. Staff Requirements. Contractor shall provide and maintain adequate Contractor Personnel and equipment to deploy to up to three (3) sites simultaneously, to respond timely for emergency repairs, and to provide emergency design/build services within the State of Tennessee. Contractor’s registered Engineer(s) involved in each project are expected to be continuously involved for the duration of each job including, but not limited to, the design phase, providing site supervision, coordinating with Authorized User’s Engineers/representatives and revising engineering plans, if necessary, based on conditions encountered during each job.

A.10. Equipment Requirements. Contractor’s equipment shall be suitable for the intended purpose as defined by the Authorized User and shall meet all federal and state Occupational Safety and Health Administration (OSHA) regulations.

A.11. Operations Requirements. All Contractor personnel shall possess the knowledge, skills, and abilities to perform all aspects of their role and operation of the equipment and to follow the practices and methods of roadway maintenance and construction used by the Authorized User, and as defined by the Authorized User. The Contractor shall ensure that all equipment operators and foremen have experience in the applicable category with the Contractor’s organization. Upon request, the Contractor shall submit documentation to a State or Authorized User Geotechnical representative showing that Contractor personnel have appropriate qualifications.

The Contractor’s personnel shall not create any hazardous condition with the operation of the equipment. All Contractor personnel shall at all times wear approved protective clothing, safety vests, and any other equipment required to meet OSHA, TDOT, and applicable Authorized User standards. Contractor’s personnel shall obey all traffic and safety rules and regulations.

A.12. AASHTO Requirements. The Contractor shall comply with AASHTO Specifications, or accepted industry standards for any specific items not addressed herein or elsewhere in the Contract.

A.13. Delay of Installation. The Contractor shall complete each individual job in a timeframe agreed upon by the Authorized User and the Contractor prior to the beginning of work in writing. This documentation shall include, at a minimum, job location, start date, agreed-upon completion date, and signatures indicating agreement by both parties. If the Contractor is unable to deliver material(s) or services within the timeframe agreed upon by the Contractor and the Authorized User the Contractor shall immediately notify the Authorized User, in writing, that material(s) or services cannot be furnished and shall provide a proposed alternate completion date and reason for delay. The Authorized User shall accept or reject the revised completion date within seventy-two (72) hours. In the event that the Authorized User rejects the proposed alternate completion date, the Authorized User reserves the right to seek an estimate from another Contractor in accordance with Section A.5. and A.6. to complete the specified job.

A.14. Mobilization/Demobilization. Contractor shall perform all work and operations necessary to load and unload equipment, move personnel, supplies, and incidentals to and from the project site to accomplish all other miscellaneous associated work items or operations that shall be performed, including cost that shall be incurred to begin work on the project and acceptable completion of construction operations on the project as defined by the Authorized User.

A.15. State/Authorized User Responsibilities

a. The Authorized User shall provide all traffic control, guardrail, public notification, clearing of the site, environmental controls, paving, backfill material, other items, and permits and shall arrange and obtain access to adjacent property as needed.

b. If the stabilization area exceeds 20 feet from the road surface, the Authorized User shall work with the Contractor on a case-by-case basis to ensure the job shall be successful. The Authorized User may provide benching and access roads for these stabilization areas of more than 20 feet. For stabilization areas less than 20 feet, the Contractor shall be expected to work from the road surface.

A.16. Other Items. Other items not included in the unit price list including, but not limited to, rock excavation, traffic control, asphalt repair, vegetation restoration, roadway subgrade excavation and guardrail removal/installation may be charged out a cost + 15% basis using the Approved Parts, Materials, Supplies and Equipment with Markup line. No work may commence that is not included in the unit prices without prior approval of the Authorized User Engineer.

A.17. Soil Nailing. Contractor(s) awarded Group One shall stabilize identified landslides by internally reinforcing the soil mass with reinforcing elements (soil nails) using installation methods as specified in this contract. Methods under Group One shall include the following:

1) self-drilling soil nails, 2) permanently cased soil nails, and 3) slope stabilization services.

The Contractor shall provide stamped engineered design and service warranty for Group One, soil nailing.

A.18. Rig and Crew Requirements. Contractor(s) awarded Group One shall have at least three (3) operational soil nail installation rigs (owned or currently leased through the Contract Term) and sufficient Contractor personnel to deploy and support three (3) locations simultaneously.

Soil nail rigs shall be capable of drilling a minimum of two hundred (200) feet in length and six

(6) inches in diameter. Equipment utilized for the standard installation of self-drilling soil nails and permanently cased soil nails, while staged on the roadway platform, shall have the ability to reach and install a soil nail a minimum of fifteen (15) feet below and twenty (20) feet above the roadway platform. Contractor shall coordinate work activities to maximize traffic flow during geohazard repairs when approved by the Authorized User’s Engineer.

A.19. Required Experience.

Contractor(s) awarded Group One shall possess the following experience and required elements of responsibility detailed below. Replacement of Contractor personnel shall only be permitted with the prior written approval of the Authorized User. The Authorized User shall receive appropriate documentation of experience for any proposed replacement Contractor personnel prior to beginning work.

a. Firm: The Contractors shall have, within the last five (5) years, successfully stabilized no fewer than ten (10) active landslides using each of the soil nail types that the Contractor is awarded to provide (i.e. self-drilling soil nails and permanently cased soil nails) on an active, public roadway while maintaining traffic on the impacted roadway.

b. Engineer: Contractor shall only use Engineer(s) with at least five (5) years of verifiable experience in landslide stabilization using soil nails. The Engineer(s) shall have successfully designed no less than ten (10) projects within the last five (5) years which successfully stabilized an active landslide using each of the soil nail types that the Contractor is awarded to provide (i.e. self- drilling soil nails and permanently cased soil nails) on an active, public roadway while maintaining traffic on the impacted roadway.

c. Project Manager/Superintendent: Contractor shall have project manager(s)/superintendent(s) who have successfully managed no less than ten (10) projects within the last five (5) years which successfully stabilized an active landslide using each of the soil nail types that the Contractor is awarded to provide (i.e. self-drilling soil nails and permanently cased soil nails,) on an active, public roadway while maintaining traffic on the impacted roadway.

d. Soil Nail Rig Operator: Contractor shall have at least three (3) soil nail rig operators who have successfully operated rigs on no less than five (5) projects within the last five (5) years which successfully stabilized an active landslide using soil nails on an active, public roadway while maintaining traffic on the impacted roadway.

e. Shotcrete Nozzle Operator: Contractor shall have at least three (3) shotcrete nozzle operators who have successfully installed at least 10,000 square feet of shotcrete in the last five (5) years to stabilize an active landslide on an active, public roadway while maintaining traffic on the impacted roadway. Upon request, Contractor shall provide current ACI certifications.

A.20. Engineering Plans. For Group One Soil Nailing, all plans must be stamped by an Engineer.

Any changes or deviations from the approved submittals must be resubmitted for approval.

No adjustments in project time shall be allowed due to incomplete submittals. The Engineer stamped submittals shall include, at a minimum, the following information:

a. A description of the construction sequence and a schedule for the work;

b. At a minimum, a description and detail of the size, length, and spacing of reinforcing elements to be placed in order to meet minimum static (1.3) and minimum seismic (1.1) factors of safety for global stability of the repair. The materials and components selected shall meet or exceed a 75-year design life. Designs shall include consideration of appropriate loadings, geometry, and material properties associated with the native soils, backfill, reinforcement connections, facing, and other design elements. Retaining wall design requires a globally stable analysis based on the contractor’s evaluation at the time of site visit; and

c. All necessary details to successfully construct any temporary/permanent facing and drainage system as defined by the Authorized User.

A.21. Self-Drilling Soil Nails. Contractor(s) awarded Group One shall furnish self-drilling soil nails that consist of a hollow, threaded bar with a sacrificial drill bit. Multiple bars may be coupled to produce final length. Bar thread pattern should be continuous and conform to the pullout requirements of ASTM A 615 (Williams Form Engineering “B7X” or Ischebeck “Titan” bars, or equivalent approved by the Authorized User’s Engineer). The Contractor shall be responsible for remaining compliant with any updates to ASTM A 615 throughout the term of this contract. Bar outer diameters shall be a minimum of 1.5 inches and up to and 3 inches depending on design load.

A.22. Permanently Cased Soil Nails. Contractor(s) awarded Group One shall furnish permanently cased soil nails that are a three-stage construction including installation of:

a. An outer tube (minimum 1.5 inch outside diameter, minimum 0.120 inch wall thickness hot- dipped, galvanized steel tube that is mechanically deformed, threaded, or specially galvanized through a drossing process to produce a plurality of surficial asperities);

b. Neat cement grout that completely fills the outer tube; and

c. An inner bar consisting of epoxy coated, #6 grade 60 or grade 75 rebar or thread bar depending on final design load. When applicable, provide perforated tubes that can be pressure grouted.

A.23. Shoulder Build-Up. Contractor(s) awarded Group One shall form and construct an additional section of roadway using standard soil nail wall configurations to widen the existing road. Contractor shall use framework materials such as stay-form, plywood, or a combination of welded wire mesh and burlap materials. These formwork materials do not contribute to the structural integrity of the soil nail wall;

they only serve to aid installation. The choice of formwork material is at the discretion of the Contractor and shall be approved by the Authorized User. The space within the form is filled with flowable fill, providing a stable base for subsequent structural work and facilitating guardrail installation.

A.24. Shotcrete. Contractor(s) awarded Group One shall furnish shotcrete complying with the requirements of ACI 506.2, “Specifications for Materials, Proportioning and Application of Shotcrete”, except as otherwise specified. Shotcreting consists of applying one or more layers of concrete conveyed through a hose pneumatically projected at a high velocity against a prepared surface.

a. Shotcrete shall be produced by either a wet-mix or a dry-mix process. The wet-mix process consists of thoroughly mixing all the ingredients except accelerating admixtures, but including the mixing water, introducing the mixture into the delivery equipment and delivering it, by positive displacement, to the nozzle. Air jet the wet-mix shotcrete from the nozzle at high velocity onto the surface. The dry-mix process consists of producing shotcrete by delivering the dry ingredients conveyed pneumatically with the mixing water introduced at the nozzle. For additional descriptive information, refer to the American Concrete Institute ACI 506R “Guide to Shotcrete.”

b. Contractor shall use materials for shotcrete conforming to the following requirements:

c. Contractor shall deliver, store, and handle materials to prevent contamination, segregation, corrosion, or damage. Liquid admixtures must be properly stored so as to prevent evaporation and freezing.

d. Contractor shall obtain Authorized User’s approval for the proposed mix design and method of placement prior to beginning shotcrete placement.

e. Contractor shall use aggregate for shotcrete meeting the strength and durability requirements of AASHTO, as applicable, and the following gradation requirements:

½” 100%

3/8” 90-100%

No. 4 70-85%

No. 8 50-70%

No. 16 35-60%

No. 30 20-50%

No. 50 8-20%

No. 100 0-10%

f. Contractor shall proportion the shotcrete to be able to be pumped with the concrete pump furnished for the work, with a cementing materials content of at least 24.3 pounds per cubic foot and water/cement ratio not greater than 0.55. Contractor shall not use admixtures unless approved by the Authorized User’s Engineer. Contractor shall thoroughly mix admixtures into the shotcrete at the rate specified by the manufacturer. Contractor shall use only accelerators that are compatible with the cement used, non-corrosive to steel, and not promoting other detrimental effects such as cracking or excessive shrinkage. The maximum allowable chloride ion content of all ingredients is 0.10% when tested to AASHTO T260.

g. Contractor shall use air entrainment for all exposed permanent shotcrete, but air entrainment is not required for temporary shotcrete construction facings.

h. Contractor shall provide shotcrete with a minimum design compressive strength of

2000 psi in three (3) days and 4000 psi in twenty-eight (28) days.

i. Contractor shall batch the aggregate and cement by weight or by volume in accordance with the requirements of ASTM C94 or AASHTO M241/ASTM C685.

Contractor shall use mixing equipment that thoroughly blends the materials in sufficient quantity to maintain placing continuity. Contractor shall produce ready mix shotcrete complying with AASHTO M157. Contractor shall batch, deliver, and place

Cement AASHTO M85/ ASTM C150, Type I, II, III or V.

Fine Aggregate AASHTO M6/ASTM C33 clean, natural.

Coarse Aggregate AASHTO M80, Class B for quality.

Water Clean and Potable. AASHTO M157/ASTM C94.

Chemical Admixture Accelerator

Fluid type, applied at nozzle, meeting requirements of

AASHTO M194/ASTM C494/ASTM C1141.

Water-Reducer and Super Plasticizer Mineral

Admixtures AASHTO M194/ASTM C494 Type B or D.

Fly Ash AASHTO M295/ASTM C618 Type F or C, cement replacement up

Silica Fume ASTM C1240, 90 percent minimum silicon dioxide solids content, not to exceed 12 percent by weight of cement.

Welded Wire Fabric Prepackaged Shotcrete

AASHTO M55/ASTM A185 or A497. ASTM C928 shotcrete within 90 minutes of mixing. The use of retarding admixtures may extend application time beyond 90 minutes if approved by the Authorized User’s Engineer.

j. Contractor may use premixed and packaged shotcrete mix for on-site mixing.

Contractor shall use packages containing materials conforming to Section A.20. of the Contract. The placing time limit after mixing shall be per the manufacturers’ recommendations.

k. To eliminate water build-up behind the shotcrete wall, the Contractor shall use strip drains that are the full width of shotcrete (down slope) at a maximum of six (6) foot centers. Strip drain details and suppliers shall be submitted and approved prior to the job’s start date by the Engineer and shall be fully encased in filter media. Drains shall extend beyond the face of the shotcrete at the downhill face.

A.25. Wire Mesh Surface Treatment (Includes Plates)

Contractor(s) awarded Group One shall furnish and install high-strength single-twist wire mesh to prevent shallow plane failures around a soil nail array. The mesh and plates must meet the following requirements:

a. Mesh Type: High strength single twist rockfall mesh

b. Wire diameter: .118 inches or greater

c. Wire Strength: 75 ksi or greater

d. Wire Coating: Minimum of 0.8 ounces/square foot (as determined by ASTM A-

90) Zinc/Aluminum Alloy (as per ASTM B750-09). Plain hot-dip galvanized is not acceptable.

e. Mesh Opening Size: 2.56 inches or smaller (using maximum circle method), area of opening shall not be less than 8.2 square inches

f. Plate Material: ASTM A36 Steel or stronger

g. Plate Coating: Hot dip galvanized in accordance with ASTM A153/A123

h. Plate Thickness: 3/8 or 1/2 inch, depending on design

i. Plate dimensions: Square or Diamond Shaped, minimum area 48 square inches

A.26. Cellular Grout. Contractor(s) awarded Group One shall provide the following: cellular grout containing foaming agents shall be a Cellular Concrete Class of I or II that produces a Cast Density of 24-35 Pcf and a minimum compressive strength at 28 days of 10-40 psi.

Compressive Strength shall be determined using ASTM C 495 as modified herein. All materials shall be delivered, stored and handled per recommendations of the cellular concrete manufacturer. Contractor(s) may use admixtures for accelerating the set time under the manufacturer’s recommendations. A foaming agent shall be used and tested in accordance with ASTM C 796. Mixing water shall be potable and free of deleterious amounts of acids, alkali, salts, oils, and organic materials. Portland cement shall comply with ASTM C 150, Types II/V. Pozzolans and other cementitious materials may be used when approved by the manufacturer of the foaming agent. Fly ash and natural pozzolans shall comply with ASTM C 618.

A.27. Retaining Wall Structure. Contractor (s) awarded Group One shall provide engineered wall systems composed of materials meeting the specifications in construction plans. Wall types to be used shall be on the TDOT Qualified Products List- 38 at the time of installation.

A.28. Self-Drilling Soil Nails Installation.

Contractor(s) awarded Group One shall:

a. Use drilling rigs capable of drilling through any materials that are encountered to the dimensions and orientations required for the soil nail wall design;

b. Drill straight and clean holes at locations shown in the accepted submittals. Drill hole locations and inclinations are required to be within 6” (150 mm) and 5 degrees, respectively, of that shown in the accepted submittals unless approved otherwise by the Authorized User’s Engineer;

c. Drill all self-drilling nails with continuous grout injection or as otherwise approved by the Authorized User’s Engineer; and

d. Assume all risks associated with unforeseen groundwater or adverse drilling conditions, including excess grout take. (Note: Grout in excess of 1.5 theoretical can be considered as Void Fill Grout Installation item.)

A.29. Permanently Cased Soil Nails Installation.

Contractor(s) awarded Group One shall:

a. Construct permanently cased soil nails by drilling a hole to prescribed depth at the prescribed location as shown on the engineering plans, inserting a 1.5 inch (or larger) outside diameter steel pipe (outer tube) to stabilize the drill hole, fully encasing the inside of the outer tube with grout (neat cement) and immediately inserting an epoxy coated #6 (or larger depending on required tensile strength) reinforcing bar as the inner bar.

b. Provide perforated tube and grout under pressure when applicable.

c. The Contractor bears the full risk of unforeseen groundwater or adverse drilling/casing conditions, including excess grout take. (Note: Grout in excess of

1.5 theoretical can be considered as Void Fill Grout Installation item.)

A.30. Shotcrete Installation.

a. Construct shotcrete with a nominal thickness of 6”, 8”, or 12” with either welded wire fabric or triple twisted galvanized wire mesh placed approximately 2” from the ground surface. The following information shall be submitted to the Authorized User for review and approval prior to the actual work:

1. All shotcrete nozzle operators shall have a current ACI shotcrete nozzle operator’s certification. Contractor shall be fully responsible for training, operation, and results of all work performed by the nozzle operators.

2. Proposed methods of shotcrete placement and of controlling and maintaining facing alignment and location and shotcrete thickness.

3. Shotcrete mix design performed by a Certified ACI Level II Technician or Tennessee Registered Professional Engineer including:

i. Type of Portland cement

ii. Aggregate source and gradation

iii. Proportions of mix by weight and water-cement ratio

iv. Proposed admixtures, manufacturer, dosage, technical literature

4. Previous strength test results for the proposed shotcrete mix completed within one

(1) year of the start of shotcreting may be submitted for initial verification of the required compressive strengths at start of production work. If the submitted test results meet the Authorized User’s approval, then further testing shall not be required. If results do not meet approval, then the Authorized User reserves the right to require further testing.

b. Not begin shotcrete construction nor incorporate materials into the work until the submittal requirements are satisfied and accepted by the Authorized User. Any changes or deviations from the accepted submittals must be re-submitted for approval. No adjustments to contract time or compensation shall be allowed due to incomplete submittals.

c. Ensure the minimum thickness of shotcrete by field measurements.

d. Clean the face of the excavation and other surfaces to be shotcreted of loose materials, mud, rebound, overspray or other foreign matter that could prevent or reduce shotcrete bond. Protect adjacent surfaces from overspray during shooting.

Avoid loosening, cracking, or shattering the ground during excavation and cleaning.

e. Remove any surface material that is loosened or damaged to a sufficient depth to provide a base that is suitable to receive the shotcrete.

f. Remove material that loosens as the shotcrete is applied. The cost of additional shotcrete is incidental to the work.

g. Divert water flow and remove standing water so that shotcrete placement shall not be detrimentally affected by standing water.

h. Do not place shotcrete on frozen surfaces.

i. Maintain a clean, dry, oil-free supply of compressed air sufficient for maintaining adequate nozzle velocity at all times.

j. Use equipment capable of delivering the premixed material accurately, uniformly, and continuously through the delivery hose.

k. Control shotcrete application thickness, nozzle technique, air pressure, and rate of shotcrete placement to prevent sagging or sloughing of freshly-applied shotcrete.

l. Orient nozzle at a distance and approximately perpendicular to the working face so that rebound shall be minimized and compaction shall be maximized.

m. Pay special attention to encapsulating reinforcement.

n. Do not work rebound back into the construction.

o. Where shotcrete is used to complete the top ungrouted zone of the nail drill hole near the face, position the nozzle into the collar of the drill hole to completely fill the void.

p. A clearly defined pattern of continuous horizontal or vertical ridges or depressions at the reinforcing elements after they are covered with shotcrete shall be considered an indication of insufficient reinforcement cover or poor nozzle techniques. In this case immediately suspend the application of shotcrete and implement corrective measures before resuming the shotcrete operations. Correct the shotcreting procedure by adjusting the nozzle distance and orientation, by ensuring adequate cover over the reinforcement, by adjusting the water content of the shotcrete mix or other means.

q. Repair shotcrete surface defects as soon as possible after placement. Remove and replace shotcrete that exhibits any of the following defects: segregation, honeycombing, lamination, voids, or sand pockets. In- place shotcrete not meeting the specified strength requirement shall be subject to remediation. Possible remediation options include placement of additional shotcrete thickness or removal and replacement, at no additional cost to the Authorized User.

r. Provide a minimum reinforcement overlap at reinforcement splice joints as detailed in

American Concrete Institute (ACI) Building Code 318. Clean and wet the surface of a joint before adjacent shotcrete is applied. Where shotcrete is used to complete the top ungrouted zone of the nail drill hole near the face, to the maximum extent practical, clean and dampen the upper grout surface to receive shotcrete, similar to a construction joint.

s. Use either an undisturbed gun finish as applied from the nozzle or a rough screed finish.

t. Shall not install shotcrete if the ground is frozen. Maintain cold weather protection if the temperature after placement is below 40°F until the in-place compressive strength of the shotcrete is greater than 725 psi. Cold weather protection may require blankets, heating under tents, or other means approved by the Authorized User.

Deposit the shotcrete mix at a temperature of not less than 40°F and not more than 100°F.

u. Suspend shotcrete application during high winds and heavy rains unless suitable protective covers, enclosures, or wind breaks are installed. Remove and replace newly placed shotcrete exposed to rain that washes out cement or otherwise makes the shotcrete unacceptable. Provide a polyethylene film or equivalent to protect the work from exposure to adverse weather.

v. The Contractor shall be responsible for meeting all federal, state, and local safety code requirements to include OSHA requirements.

w. Use six (6) to twelve (12) inch strip drains full width of shotcrete (down slope) at six

(6) foot centers to eliminate water build-up behind the shotcrete wall. Strip drains shall be fully encased in filter media. Drains shall extend beyond the face of the Shotcrete at the downhill face by the length required by the Authorized User.

Ensure that bottom ends are open and free of shotcrete. Contractor shall make all reasonable efforts to protect installed strip drains from damage during construction.

A.31. Wire Mesh Surface Treatment Installation.

a. Ensure that the mesh shall be stretched tight across the slope and over the nail tips;

b. Dig shallow depressions at least 12 inches in diameter and at least 8 inches deep around the nail tips; and

c. Install galvanized steel plates over the nail tips and post-tensioned to up to 10,000 pounds- force, as specified on the engineering plans provided by the Contractor and agreed upon by the Authorized User. Torque-tension relationships may be used to verify appropriate loading.

A.32. Soil Nail Sampling and Testing.

Contractor(s) awarded Group One shall comply with the following:

a. Prior to acceptance of the soil nails, the Contractor shall certify to the Authorized User that the material composition and installation conforms to these specifications, combined with visual inspection of the in-place soil nails and shotcrete by the Authorized User. The Authorized User reserves the right to require testing by the Contractor. Any requested testing of the soil nails shall follow appropriate procedures as outlined in Federal Highway Administration (FHWA) Geotechnical

Engineering Circular No. 7 and/or manufacturer’s recommendations. Materials found not in compliance with the requirements of this Contract may be rejected, removed and replaced at the Contractor’s expense. An Authorized User representative shall be present during any nail testing.

b. Proof tests are intended to verify that there are no significant variations in soil nail performance throughout the wall. The Contractor shall provide proof testing as required per the latest revision of FHWA -NHI-007 “Soil Nail Walls Reference Manual”.

c. Verification tests shall be completed on non-production, “sacrificial” nails prior to construction. Verification testing may be required during production to verify capacities for different in situ conditions encountered during construction and/or different installation methods. The verification tests shall be conducted on nails as considered in design and constructed with the same construction methods to be used on production nails. It would be optimal for verification tests to reach pullout, which is defined as the test load at which attempts to further increase the test load increments result in continued movement of the tested nail, when the maximum test load is applied. The Contractor shall provide verification testing as required per the latest revision of FHWA -NHI-007 “Soil Nail Walls Reference Manual”.

d. Shotcrete Testing – The Contractor shall provide a shotcrete mix design for approval once per calendar year to TDOT’s Materials and Tests Division. Once approved, shotcrete testing per the TDOT’s Construction Specifications shall be waived and the specifications in this contract shall govern for projects performed under this contract.

A.33. Cellular Grout. Cellular Grout provided by the Contractor(s) awarded Group One shall be job site mixed with foaming agent and placed with equipment specialized for cellular concrete lightweight material. Cement and water may be premixed and delivered to the job site and foaming agent added on site. Once mixed, the cellular concrete shall be conveyed promptly to the location of placement without excessive handling. If ambient temperatures are anticipated to be below 32 degrees F within 8 hours after cellular concrete placement, mixing water shall either be heated as approved by foaming agent manufacturer or placement shall be prohibited.

A.34. Vertical Reinforced Element. Contractor(s) awarded Group One shall provide vertical reinforced element when roadway build-up reaches up to five feet. The vertical reinforced element consists of an A-wall configuration. In an A-Wall application, the build-up is used for the full height of the wall, requiring additional formwork.

A.35. Retaining Wall. The retaining wall structure provided by the Contractor(s) awarded Group One shall be constructed to lines and grades determined by the plans as required in Sections A.8.

and A.23 of the Contract. Backfill shall be provided by the Authorized User or bid item “Select Granular Backfill”. The item “Select Granular Backfill” cost shall only include the cost of the material and transport to the project location; all other costs in handling, placing, grading, and compacting is to be included in other bid items. It shall be the Contractor’s responsibility to select, place, and compact the material in accordance with the design of the retaining wall structure. All combinations of backfill and geosynthetic reinforcement materials shall be based on the plans developed as outlined in section A.8. All geosynthetic reinforcement materials shall be on the TDOT Qualified Products List 36 at the time of installation.

A.36. Geosynthetic Reinforcement Fabric. Contractor(s) awarded Group One shall provide polymeric geosynthetic materials to stabilize terrain. The Contractor’s Engineer shall submit the type of geosynthetic material recommended for each project to the Authorized User Engineer for approval prior to use.

A.37. Galvanized Wire Baskets or Welded Wire Form. Contractor(s) awarded Group One shall provide double twisted galvanized wire or welded wire form baskets to be filled with gabion for the construction of retaining walls and soil stabilization.

A.38. Horizontal Drains.

Contractor(s) awarded Group Two shall provide and install horizontal drains.

Horizontal drains consist of 1.5-inch diameter (or larger) slotted schedule 80 (or thicker) polyvinyl chloride (PVC) plastic pipe conforming to the requirements of ASTM Designation: D 1785. These pipes are inserted into drilled holes to reduce water pressures within slide masses.

Pipe Slots/Perforations: Slotted pipe shall have two (2) rows of slots. The rows shall be in the longitudinal direction of the pipe and the slots shall be cut in the circumferential direction of the pipe. The rows shall be centered on two (2) of the third points (120 degrees apart) of the pipe circumference. Each row of slots shall conform to one of the following configurations.

Slots shall be spaced uniformly along the pipe. The minimum opening shall be measured on the inner surface of the pipe.

Number of Slots (±1) per Linear Foot

Width of Slot (Inches)

Minimum Opening per Linear Foot

(Square Inches)

46 0.010 0.46

Perforated pipe shall have three (3) rows of perforations with one row on each side of the pipe and the third row in the top. Fittings for the PVC plastic pipe shall be Schedule 80 Type II PVC solvent weld type fittings conforming to the requirements in ASTM Designation: D 2467.

Machined male and female ends may be used in lieu of couplings. Unslotted or unperforated PVC plastic pipe, between 5 ft to 20 ft length, shall be provided at the outlet of the drain.

A.39. Class A Concrete. All class A concrete installed by Contractor(s) awarded Group Three shall meet requirements of section 604 of the STANDARD SPECIFICATIONS FOR ROAD AND BRIDGE CONSTRUCTION Revised January 1, 2025, as well as being produced by a supplier in good standing at the time of placement.

A.40. Offset Drilling.

a. Contractor(s) awarded Group Three shall provide modified rotary drill, truck, rubber tire or track mounted with operator to drill 7 inch to 10 inch diameter holes in soil and rock to install (in place) steel railroad rails up to 39 feet in length and weighing up to 140 lbs. per linear yard. Rotary Drill shall have capability of drilling holes that are offset a minimum of five (5) feet from the edge of the truck tire or track (if track mounted) to the center of the hole. Drill rig shall be capable of handling steel railroad rail up to 39 feet in length. Drill rig should be powered by motor of 130 horsepower or greater with at least 16,000 lbs.

pulldown pressure and a 300 CFM or greater air compressor. Drill rig shall be capable of drilling from either side or back of carrier.

b. Drill shall have capability of drilling to a minimum of forty (40) foot holes from elevation of roads. Contractor shall be able to drill and install eight hundred (800) feet of railroad steel per 8-hour workday. Leeway shall be given for weather and unforeseen circumstances at the Authorized User’s discretion.

A.41. Rail. Contractor(s) awarded Group Three shall use recycled railroad rails classified with a nominal weight of 130 lb/yd (pounds per yard) size or greater. Use only visibly straight recycled railroad rails with no splices. The Engineer shall verify rail nominal weights (manufacturer’s stamp with lb/yd, date, etc.). Provide certification for nominal weight if the manufacturer’s stamp is unidentifiable.

A.42. Cribbing. Contractor(s) awarded Group Three shall install cribbing as slide location dictates or as directed by the Engineer. Extend wall cribbing two (2) feet below the existing ground line as measured from the back side of the installed railroad rails. If bedded rock is encountered, install the cribbing to the bedded rock only. The Engineer shall direct changes if necessary, to this procedure. Wall cribbing shall be lapped, bolted, and attached solid to the drilled railroad rails. Use wall cribbing: recycled steel "w" beam guardrail.

A.43. Rockfall Mitigation. Contractor(s) awarded Group Four shall provide services as specified on the engineering plans provided by the Contractor and agreed upon by the Authorized User.

a. Rock Scaling is the removal of loose and unstable rock and debris from the existing slopes to a safe, stable condition. This is achieved by removing all loose spalls and rocks not firmly keyed into the slopes. This is accomplished by using manual devices such as pry-bars, removal by hand, as well as the use of hydraulic, pneumatic, or other jacks, hydraulic hammers. The Contractor shall be required to scale the existing slopes within the limits shown on the plans and as determined by the Engineer and dispose of all material removed resulting from the scaling operation.

b. Trimming is the process of removing overhangs of loose and unstable rock from a cut slope by mechanical percussion and/or blasting methods. This includes ''blast scaling'' and air cushion blasting. Where air cushion blasting is used, blast holes shall be 2 inches or less in diameter.

c. The rock slopes shall be thoroughly scaled by manual means. If manual means prove insufficient and if directed by the Engineer, the slopes shall be drilled and blasted, or air cushion blasting shall be utilized to remove the hazardous rock.

d. In the event the Contractor is directed to perform scaling on a slope previously approved as complete by the Engineer, the additional scaling shall be measured and paid for at the contract unit price for ''Scaling''. Scaling operations may require multiple scaling efforts across the slope during a project. For example, this may be required to make areas safe for other work, or where blasting shall be conducted scaling may be required after blasting is complete.

e. The Contractor is advised that since scaling operations shall entail considerable hazards due to falling rock and debris, the traveling public shall be adequately protected from falling rocks and debris by installing, before scaling and trimming operations are started, temporary rockfall barriers or other devices as approved by the Engineer.

f. Rock Blasting. In areas where blasting shall be required and approved by the Engineer this item shall be paid for per Cubic Yard of material generated from the blasting procedure. Measurement of the volume shall be done by truck load and the volume per truck shall be approved by the Engineer or inspector on site. Drilling for the blasting shall be paid for under the appropriate drilling item in the unit prices.

The unit price for blasting shall be full compensation for all blasting materials, pre-blast surveys, placement of dynamite, detonation of the blast, loading and hauling of the material, and disposal.

g. Temporary Rockfall Protection. The types of temporary rockfall protection shall vary greatly from site to site and could be as little as the installation of jersey barriers up to 2 cranes suspending Type III wire mesh fabric. Because of this the extent of the temporary rockfall protection shall be determined on a site-by-site basis with prior approval by the Authorized User Engineer and paid out on a cost-plus basis.

h. Rock Sizing. If the scaled or blasted material is too big for the equipment on site to manage, or for the dump trucks to dump, the blocks shall be sized to make them more manageable. This shall be accomplished by either drilling holes and utilizing a Boulder Buster or by utilizing a hydraulic breaker to break the blocks into manageable sizes.

Rock sizing shall be paid for by cubic yard of the block being sized. Determination of the individual blocks shall be approved prior to the work by the Engineer or by the inspector on site.

i. Concrete Buttress. Concrete buttress consists of shotcrete placed on the slope to reinforce rock structures that have been undercut by weathering or other means. A concrete buttress shall be installed when a key block requires further reinforcement and removal of that key block would create a global instability and create increased costs in stabilizing the rock slope. Concrete buttress shall be paid out per cubic yard successfully installed on the rock slope.

j. Thread Bar. Thread bar in all sizes noted in the unit prices shall be full payment for an installed fully grouted rock anchor. Payment shall be for every linear foot successfully installed of rock anchor.

k. Anchor Testing. If required by the State either verification or proof testing shall be performed on the installed anchors. The type of testing and quantity of tests shall be determined by the Engineer. Payment shall be made for every anchor successfully tested on site.

l. Wire Mesh Fabric. Wire mesh fabric shall be for all types as described in the unit prices successfully installed on the slope. Payment shall be for every square foot of wire mesh fabric successfully installed.

m. Horizontal Drainpipes. Drainpipes as specified in section A.32 shall be installed in locations chosen by the Engineer. Payment for horizontal drains shall be for every linear foot of horizontal drainpipe successfully installed. Drilling for the drainpipes shall be paid out at the unit price as either high reach or low reach drilling.

n. Limited Access Shotcrete/Gunite. Limited access shotcrete shall be installed in locations and at a thickness determined by the Engineer. Limited Access is defined as areas that are difficult to reach as defined by the Authorized User. Shotcrete is pneumatically installed on the slope as a wet mix and applied in lifts. Gunite is shotcrete installed as a dry process where the water is introduced at the nozzle by the nozzleman. Fiber reinforcement shall be added as determined by the Engineer.