17-R-0019-0004-2.pdf

Amendment 0004

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 22 23.99 15

SLIDE REPAIRS WITH LIME TREATMENT (PL84-99)

PART 1 GENERAL

1.1 SCOPE

1.2 REFERENCES

1.3 SUBMITTALS

1.4 SUBMITTAL DESCRIPTIONS

1.4.1 Plan of Fill and Backfill Operations

1.4.2 Testing Plan

1.4.3 Survey Records

1.4.4 Fill and Backfill Materials

1.4.5 Contractor-furnished Rights-of-way

1.4.6 Contractor-furnished Borrow Area(s)

1.4.7 Commercial-furnished Materials

1.5 QUALITY CONTROL

1.6 NEW SLIDES

1.7 1.7 LEVEE CLOSURE UNDER EMERGENCY FLOOD CONDITIONS

1.8 TREE TRIMMING

1.9 WORK ADJACENT TO EXISTING FEATURES

1.9.1 Slide Repairs at Drainage and Closure Structures

PART 2 PRODUCTS

2.1 SATISFACTORY MATERIALS

2.1.1 General

2.1.2 Suitable Embankment Material

2.1.3 Topsoil

2.1.4 Unsuitable Material

2.1.5 Hydrated Lime

2.1.6 Water Quality

2.2 EARTHWORK EQUIPMENT

2.2.1 General

2.2.2 Crawler-Type Tractors

2.2.3 Sheepsfoot Rollers

2.2.4 Water Truck

2.2.5 Spreading Equipment

2.2.6 Soil Stabilizer/Pulverizer

2.2.7 Miscellaneous Equipment

PART 3 EXECUTION

3.1 EXCAVATIONS

3.1.1 Topsoil Removal (Stripping of Repair Areas)

3.1.2 Inspection Trench

3.1.3 Slide Excavation

3.1.4 Surplus and Insufficient Material

3.1.4.1 Surplus Material

3.1.4.2 Insufficient Material

3.1.5 Placement of Excavated Materials

SECTION 31 22 23.99 15 Page 1

3.1.5.1 Suitable Embankment Materials

3.1.5.2 Unsuitable Materials

3.2 MATERIALS TESTING

3.2.1 General

3.2.2 Standard Compaction Tests

3.2.3 Soil Density Testing

3.2.4 Hydrated Lime

3.2.5 Water (Moisture) Content Tests

3.2.6 Quality Assurance

3.3 HYDRATED LIME TREATMENT OF EMBANKMENT MATERIALS

3.3.1 General

3.3.2 Initial Lime Application

3.3.3 Final Lime Application

3.4 LEVEE EMBANKMENT RESTORATION

3.4.1 Foundation Preparation

3.4.2 Moisture Control

3.4.3 Placement

3.4.4 Compaction

3.4.4.1 Requirements

3.4.4.2 Drain Lines and Closure Structures

3.4.5 Replacement of Topsoil

3.4.6 Scarifying

3.5 GRADE TOLERANCES

3.6 SURVEYING MONUMENTS

-- End of Section Table of Contents --

SECTION 31 22 23.99 15 Page 2

SECTION 31 22 23.99 15

SLIDE REPAIRS WITH LIME TREATMENT (PL84-99)

PART 1 GENERAL

1.1 SCOPE

The work covered by this section consists of furnishing all labor and equipment, and performing all operations in connection with slide excavation, foundation preparation, lime treatment and stockpiling of excavated materials, and reconstruction of the levee embankment at the slide area.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

ASTM INTERNATIONAL (ASTM)

ASTM C 207 Hydrated Lime for Masonry Purposes

ASTM D 698 Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft.-lbf/ft (600 kN-m/m)) (305mm) Drop

ASTM D 1556 Density and Unit Weight of Soil in Place By The Sand-Cone Method

ASTM D 2216 Laboratory Determination of Water (Moisture) Content of Soil and Rock

ASTM D 2487 Classification of Soils for Engineering Purposes (Unified Soil Classification System)

ASTM D 2937 Density of Soil in Place by the Drive-Cylinder Method

ASTM D 4318 Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D 4643 Determination of Water (Moisture) Content of Soil by Microwave Oven Heating

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. The following shall be submitted in accordance with Section 01 33 00 - SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

SECTION 31 22 23.99 15 Page 3

Plan of Fill and Backfill Operations; G Testing Plan; G

SD-06 Test Reports

Survey Records; G Fill and Backfill Materials

SD-07 Certificates

Hydrated Lime; G The Contractor shall submit a certification of compliance for hydrated lime.

Contractor-furnished Rights-of-way Contractor-furnished Borrow Area(s); G Commercial-furnished Materials; G

1.4 SUBMITTAL DESCRIPTIONS

1.4.1 Plan of Fill and Backfill Operations

The Contractor shall submit for review and approval by the Contracting Officer, 10 days prior to placing material in fills and backfills, the plan of operations for accomplishing all fills and backfills specified herein.

The plan shall contain, as a minimum but not be limited to, the following:

(a) The Contractor's proposed sequence of construction in accordance with these specifications for stockpile, fill and backfill items. The plan shall describe, as a minimum but not be limited to, the following:

satisfactory stockpiling and lime treatment of the excavated material, construction of satisfactory compacted slide repair areas, and all other fill and backfill work items that are shown on the drawings.

(b)The Contractor's proposed list of equipment types and quantities of each equipment type to be utilized for fills and backfills operations.

(c) The Contractor's proposed methods for transporting, placing, and compacting the fills and backfills.

(d) The Contractor's proposed methods for providing drainage prior to, during, and after placement of partially completed and completed fills and backfills. The surface sealing of the fill and backfills to minimize precipitation infiltration prior to periods of inactivity such as the end of each work day and rain stoppages.

(e) The Contractor's plan shall include the names and addresses of the commercial testing labs or engineering firms which will perform the soil testing and inspection and describe how all required soils testing will be performed.

1.4.2 Testing Plan

Submit a testing plan for all in-place soil density testing to be performed by the Contractor or representative. The plan shall include the name of the testing company, an indication of whether there will be offsite or onsite testing. The Contractor shall describe how all required soils testing will be performed to include but not limited to obtaining untreated samples of slide material, procedures for performing ASTM D 698 per paragraph MATERIALS TESTING, General, and method of selecting sampling

SECTION 31 22 23.99 15 Page 4 location for each stage of work.

1.4.3 Survey Records

A copy of the records of each compliance survey shall be provided the Contracting Officer the next work day following the survey.

1.4.4 Fill and Backfill Materials

At least 7 days prior to placement of fill and backfill materials, the Contractor shall submit testing results from tests performed in accordance with paragraph MATERIALS TESTING. The Contractor shall submit all raw data sheets, computation sheets, and laboratory results of the required tests of the proposed materials.

1.4.5 Contractor-furnished Rights-of-way

If the Contractor proposes to use private property for drainage, stockpiles, and haul roads, the Contractor shall submit written evidence to the Contracting Officer that the right has been obtained from the property owner. The written evidence shall consist of an authenticated copy of the conveyance under which the Contractor acquired the property rights and access thereto, prepared and executed in accordance with applicable state and local laws and regulations.

1.4.6 Contractor-furnished Borrow Area(s)

The Contractor shall submit a written certification that the proposed borrow material contains no hazardous and/or toxic substances. The Contractor shall also submit written certification that the proposed borrow area(s) will not significantly impact the environment and wetlands. The Contractor shall also submit written certification of historic and cultural resource clearance(s) that shall consist of a signed letter of concurrence from the appropriate State Historic Preservation Officer (SHPO). SHPO clearance will require one of the following: 1) evidence that the area includes no significant historic resources and that the existing ground surface within the proposed site has been previously disturbed to the extent that archaeological features would have been destroyed; or 2) evidence that a professional archaeological assessment of the area demonstrates that the location contains no significant archaeological remains. The Contractor shall submit written evidence to the Contracting Officer that the Contractor has obtained property rights and access to the approved borrow area(s). The written evidence shall consist of an authenticated copy of the conveyance under which the Contractor acquired the property rights and access thereto, prepared and executed in accordance with the laws of the State of Illinois. The Contracting Officer reserves the right to approve or disapprove the use of Contractor-furnished borrow areas.

1.4.7 Commercial-furnished Materials

The Contractor shall submit commercial certificates showing evidence of compliance to the contract specifications.

1.5 QUALITY CONTROL

The Contractor shall establish and maintain quality control for all excavation, fill, and backfill operations to assure compliance with contract requirements, and maintain records of the quality control for all

SECTION 31 22 23.99 15 Page 5 construction operations including but not limited to the following:

(a) Earthwork Equipment. Earthwork equipment shall be identified by type, model, size, number of units and suitability for construction of the prescribed work.

(b) Inspection Trench. Excavation of an inspection trench at each levee slide location to determine the failure zone.

(c) Grade Tolerances. Check fills to determine if placement conforms to prescribed grade and cross section.

(d) Backfill Placement. Backfill lift thickness, material moisture control, and compaction of materials for the embankment backfill.

(e) Material Testing. Material testing shall be performed by the Contractor for all control testing specified in paragraph MATERIALS TESTING. The Contractor shall perform the required number of each, and any additional testing as specified herein when requested by the Contracting Officer to demonstrate to the satisfaction of the Contracting Officer that the Contractor is complying with these specifications. Control testing and inspection shall be the responsibility of the Contractor and shall be performed at no additional cost to the Government by an approved commercial testing laboratory or engineering firm which performs soil and material testing and inspection. All testing locations shall be accurately located in reference to levee stationing, offset from levee centerline and elevation.

1.6 NEW SLIDES

Prior to commencing any part of this work, the Contractor and Contracting Officer shall jointly inspect the entire contract area to verify the slide repairs as shown on the drawings, and to record and verify other existing slides which have occurred subsequent to drawings preparation. The Contractor shall be responsible for immediately notifying the Contracting Officer of any new slides which develop subsequent to the joint inspection. In case a new or unrecorded slide is caused through fault of the Contractor, the slide shall be repaired without additional cost to the Government.

1.7 1.7 LEVEE CLOSURE UNDER EMERGENCY FLOOD CONDITIONS

In the event of a flood emergency, the Contracting Officer reserves the right to direct the closure of any opening(s) constructed by the Contractor. Prior to placing the embankment, the bottom and side slopes of the notch shall be broken or scarified to a depth of 6-inches and compacted. The stockpiled material shall be used for the embankment and shall be placed and compacted as specified. Upon written notification of a flood emergency, the Contractor shall immediately begin and execute the closure operations in a timely manner. Payment for emergency closures will be paid for by an equitable adjustment to the contract price in accordance with SECTION 00700, CONTRACT CLAUSE entitled "Changes".

1.8 TREE TRIMMING

To facilitate slide repair construction efforts on the landside of the levee the Contractor may trim trees limbs, with approval from the Contracting Officer's Representative. The Contractor shall not trim tree

SECTION 31 22 23.99 15 Page 6 limbs higher than 15 feet above the existing ground. Limbs shall be trimmed at the trunk of the tree by means of mechanical saws only.

1.9 WORK ADJACENT TO EXISTING FEATURES

Except for those instances where the road on the levee is affected by the slide repair, the Contractor shall not otherwise stockpile excavated materials, store materials or supplies, operate or store equipment in such a manner as to adversely affect the use or operation of any roadways or improvements such as gravity drains, relief wells, piezometers, fencing, hiking trails, etc. The Contractor shall not remove or alter any improvements in order to accomplish the repairs, unless approved by the Contracting Officer.

1.9.1 Slide Repairs at Drainage and Closure Structures

Some slide repairs may be located adjacent to or over gravity drain pipes and structures or closure structures. The equipment and construction procedures used shall prevent damage to any part of the drainage structure, gate structure or closure structures. The Contractor's plan of operation shall include an approved method of detecting horizontal and vertical movement or deflection in the drainage structure.

Appropriate field survey type instruments and targets may be used for the purpose of detecting movement or deflection. Prior to beginning the slide excavation, the Contractor shall furnish and temporarily attach the survey points or targets to the discharge structure in a non-damaging manner. A trained or experienced instrument operator, furnished by the Contractor, shall read the target(s) before any work is performed at the slide repair, and during each pass of the equipment and in a manner and as often as necessary to detect movement during the repair operations.

The instrument operator shall alert the Contractor when initial movement takes place and shall immediately notify the Contractor of movement that exceeds the limits specified herein. Operations shall cease in the event that movement or deflection is detected that exceeds 0.25 inches. The Contractor shall perform the initial slide excavation down to the failure surface, except when the movement or deflection limits are exceeded.

When conditions arise which cause the Contractor to revise its original plan of operations, the Contracting Officer may order that the resulting work be performed under the Contract Clause entitled, "Changes." The Contracting Officer may direct that the preceding inspection and monitoring be applied to any other drainage structures that may be affected by the repair requirements of this contract.

PART 2 PRODUCTS

2.1 SATISFACTORY MATERIALS

2.1.1 General

The excavated slide areas in the levee embankment shall be restored to the prescribed section as shown on the drawings with lime treated materials obtained from the stockpiles. All materials from the slide area shall be placed in the stockpile according to all provisions of paragraph Placement of Excavated Materials, General. Levee restoration materials shall be free

SECTION 31 22 23.99 15 Page 7 from unsuitable materials and frozen materials.

2.1.2 Suitable Embankment Material

Suitable embankment materials shall be clays (CL, CH) or silts (ML) as classified by ASTM D 2487. If sand is encountered in the excavation, the sand shall be blended with less pervious materials to the extent that it will classify as suitable material. Suitable materials for slide repairs shall be the failed material excavated from the levee embankment. If additional materials are needed to finish the slide repairs the Contractor can use commercially furnished and approved materials.

2.1.3 Topsoil

Topsoil includes selectively excavated material that is representative of local soils that produce crops, grass, or other vegetation, and is free from litter, wood, limbs, brush, matted roots, toxic substances, or any material harmful to plant growth or which would hinder grading, planting or maintenance operations. Topsoil shall not contain more than 1 percent by weight of stones or other such objects larger than 1 inch in any dimension.

2.1.4 Unsuitable Material

Organic matter, sticks, branches, sod, humus, roots, and other debris shall be considered unsuitable.

2.1.5 Hydrated Lime

Hydrated lime shall meet the requirements of ASTM C 207, Type N. The lime shall be delivered to the work sites in bulk trucks or bags. If delivery is to be in bulk form, the bulk truck container shall be fully enclosed and dust-proofed and be self-unloading. Otherwise, the lime shall be stored in Contractor-furnished weatherproof sheds, bins or by other approved methods. At no time shall the lime be dumped or stockpiled on the ground or otherwise left exposed or unprotected from the weather.

2.1.6 Water Quality

Water which has been approved by a public health agency for drinking or ordinary household use may be used. Water from stagnant, shallow or marshy surfaces shall not be used. Pipeline intakes in flowing streams and rivers shall be enclosed to exclude silt, mud, grass and other solid materials and there shall be a minimum depth of 2 feet of water under the intake at all times. In addition, water obtained from other than State approved sources shall be free from oil, acid, alkali or any other substances deleterious to the soil-lime mixture.

2.2 EARTHWORK EQUIPMENT

2.2.1 General

The Contractor shall use equipment as specified and as shown on the drawings. All equipment shall be field checked under the direction and supervision of the Contracting Officer prior to their use to assure that the required results can be obtained. Any equipment that does not produce the required results will not be allowed. Not all equipment listed shall necessarily be used.

SECTION 31 22 23.99 15 Page 8

2.2.2 Crawler-Type Tractors

Crawler-type tractors used for spreading shall weigh not less than 20,000 pounds, shall exert a unit tread pressure of not less than 6 pounds per square inch, and shall be operated at speeds not to exceed 3.5 miles per hour. The treads of crawler type tractors shall not be used to compact the impervious embankment.

2.2.3 Sheepsfoot Rollers

Sheepsfoot rollers shall consist of one or more units. Each unit shall consist of a cylindrical drum not less than 60 inches in length and not less than 60 inches in diameter. The drums shall be water, or sand and water ballasted. Each drum shall have staggered feet uniformly spaced over the cylindrical surfaces so as to provide approximately 3 sheepsfeet for each two square feet of drum surface. The sheepsfeet shall be 7 to 9 inches in clear projection from the cylindrical surface of the roller, and shall have a face area of not less than 5 nor more than 10 square inches.

The weight of the roller when fully loaded shall not be less than 4000 pounds per linear foot of drum length and when empty shall not be more than 2500 pounds per foot of drum length. The Contractor will be required to vary the amount of ballast in the drums to obtain optimum compactive effort for the material being compacted. The rolling units shall be equipped with a suitable device for cleaning the feet. The rolling units of multiple-type sheepsfoot rollers shall be pivoted on the main frame in a manner which will permit the units to adapt themselves to uneven ground surfaces and to rotate independently. The roller shall not exceed 3.5 miles per hour.

2.2.4 Water Truck

A water truck shall have a minimum capacity of 2000 gallons and be fitted with variable spray nozzles. Sprinkling equipment shall be designed to apply water uniformly and in controlled quantities to variable widths of surface. The Contractor shall furnish water from approved sources that meets the requirements of paragraph Water Quality.

2.2.5 Spreading Equipment

Spreading equipment shall be capable of spreading and blending materials in horizontal layer thickness between 6.0 and 10.0 inches.

2.2.6 Soil Stabilizer/Pulverizer

Variable speed soil stabilizer/ pulverizer shall be equipped with rotor and cutting teeth designed to blend additives with cohesive soil types capable of mixing to a minimum depth of 16 inches with a minimum cutting speed of 170 rpm.

2.2.7 Miscellaneous Equipment

Scarifiers, disks, and other equipment shall be of types suitable for construction of levee repair backfills and embankments and acceptable to the Contracting Officer.

SECTION 31 22 23.99 15 Page 9

PART 3 EXECUTION

3.1 EXCAVATIONS

3.1.1 Topsoil Removal (Stripping of Repair Areas)

The topsoil of the levee restoration area shall be excavated down to a depth of 6 inches and stockpiled along the berm of the levee for later use. The topsoil shall be replaced on the restored levee section.

3.1.2 Inspection Trench

After the topsoil has been removed, an inspection trench shall be excavated at each slide location at the direction of the Contracting Officer. The Contracting Officer will direct the location and depth to determine the extent of the failure zone. The trench shall be a minimum of 8 feet wide with one vertical face and the other sloped back no steeper than 1 Vertical on 1.5 Horizontal after the slide failure surface has been identified.

After the failure surface has been identified, the Contractor, upon order from the Contracting Officer, shall then proceed with the full excavation of the slide area. The Contractor shall obtain samples of each different soil types for classifications results. The classifications tests shall be performed in accordance with ASTM D 2487 and ASTM D 4318. In the event that the Contractor will not begin work to repair the slide within 24 hours after this inspection, the inspection trench shall be backfilled at no cost to the Government. Compaction of this backfill is not required.

3.1.3 Slide Excavation

The material in the slide areas shall be excavated to the approximate excavation lines indicated on the drawings but shall at all times be excavated beyond the failure surface. The final limits, lines, and depths of such excavation shall be as directed by the Contracting Officer. At no time shall the materials in the slide areas, except for the inspection trenches, be excavated to a slope steeper than those indicated on the drawings. The excavations shall be made in such a manner as to provide drainage away from the levee at all sites. Excavation of the slides shall be performed with a dragline, backhoe, scraper or other approved equipment;

however, at no time shall equipment be allowed to place a surcharge on the levee which may induce an additional failure. The materials shall be excavated commencing at the top of each slide and progressing downward.

Immediately after the slide excavation is completed and approved by the Contracting Officer and before preparing the foundation area, cross-section surveys that are to be used for measurement and computation of quantities will be taken by the Contractor.

3.1.4 Surplus and Insufficient Material

3.1.4.1 Surplus Material

Subject to the Contracting Officer's approval, surplus material from the slide repair operations shall be uniformly placed to flatten the levee slopes.

3.1.4.2 Insufficient Material

If the amount of suitable excavated levee material is insufficient to construct the prescribed levee section as shown on the drawings, the Contractor shall obtain additional suitable material from a commercially

SECTION 31 22 23.99 15 Page 10 available borrow source. Suitable borrow material shall be stockpiled and treated according to all applicable provisions of paragraph Placement of Excavated Materials, General.

3.1.5 Placement of Excavated Materials

All excavated material shall be stockpiled within the existing levee right-of-way on the landside or riverside berm as required. The stockpile areas shall be stripped in accordance with SECTION 31 21 10.99 15 prior to placement of any stockpiled materials. The material excavated from the slide excavation shall be placed and spread in 10 inch lifts in the stockpile. Each lift shall receive the initial lime application specified in paragraph Initial Lime Application prior to placing the next lift of excavated material. The top most lift shall mellow/cure a minimum of 24 hours after mixing before making the final lime application specified in paragraph Final Lime Application. Excavated materials shall not be stockpiled on the levee. The Contractor shall return all work areas to preconstruction conditions.

3.1.5.1 Suitable Embankment Materials

Suitable embankment materials shall be stockpiled as defined in paragraph Placement of Excavated Materials, General. The stockpile areas shall be stripped in accordance with SECTIONS 31 21 10.99 15 prior to placement of any stockpiled materials.

3.1.5.2 Unsuitable Materials

Unsuitable materials shall be disposed of off site by the Contractor in accordance with all local, state and federal regulations at no additional cost to the Government.

3.2 MATERIALS TESTING

3.2.1 General

The Contractor shall have an onsite testing lab for all material testing procedures as specified herein during the life of the slide repairs contract. If the onsite testing lab is considered to be a satellite lab from a parent company, then the parent company shall be validated. All calibration records and procedures shall be onsite and available for review by the Government. The Government reserves the right to inspect the lab at any time. The Contractor shall make all changes based on the inspection.

3.2.2 Standard Compaction Tests

The moisture-density relation of the treated embankment material for the levee restoration shall be performed in accordance with ASTM D 698, Method A except for the following field proctor procedures: A sample of soil shall be obtained immediately around each soil density test. The soil shall be passed thru a No. 4 sieve. After the soil is passed thru a No. 4 screen, three or more specimen is weighed for each field proctor. Water content for each specimen is then adjusted to bracket the estimate optimum water content. Water adjustment between specimens should be approximately 2%.

The sieved material may have to be air dried using a fan. After the adjustments to the water content is completed, proceed with paragraph 10.4 of ASTM D 698 to complete the procedures. Determination of water content shall be performed in accordance with paragraph Moisture Control.

SECTION 31 22 23.99 15 Page 11

3.2.3 Soil Density Testing

The soil density of the fill and backfill materials shall be tested in accordance with ASTM D 1556 or ASTM D 2937. For every density determination, a standard compaction test shall be taken within 2 feet.

Embankment materials below mid-levee slope shall be tested every 18 inches vertically, and randomly staggered in the fill and backfill areas as specified in paragraph QUALITY CONTROL. Embankment materials above mid-levee slope shall be tested every 24 inches vertically, and randomly staggered in the fill and backfill areas as specified in paragraph QUALITY CONTROL. The in-place soil density shall be compared with the standard compaction test specified in paragraph MATERIALS TESTING, General. Test results from a nuclear densometer will not be accepted for quality control record tests.

3.2.4 Hydrated Lime

The quantity of hydrated lime applied to the embankment materials shall be verified for each lime application. A piece of canvas or heavy plastic (6-mil minimum), measuring 3 feet by 3 feet, shall be placed randomly on the stockpile area prior to the lime application. The lime deposited on the canvas shall be weighed on a scale approved by the Contracting Officer to within one tenth (0.1) pound. The quantity of lime shall not be less than specified.

3.2.5 Water (Moisture) Content Tests

Determination of water content shall be performed in accordance with ASTM D 2216. Water content tests from microwave ovens performed in accordance with ASTM D 4643 can be used for record test results provided the following are met: The percent compaction compare to the oven results is within the range of plus or minus 1.50% and also the difference from optimum moisture content compare to the oven results is within the range of plus or minus 1.50%. If either or both compaction and moisture content requirements fall outside the 1.5% allowance, then the oven dried results shall govern.

3.2.6 Quality Assurance

As a control, the Government will perform assurance and check tests for soil compaction, optimum water content, and water content of treated embankment material.

3.3 HYDRATED LIME TREATMENT OF EMBANKMENT MATERIALS

3.3.1 General

The Contractor shall treat the excavated material with two applications of hydrated lime. The initial lime application shall be applied and mixed upon excavation of material from the levee slide to allow the treated material to cure. The final lime application shall be applied not more than 8 hours prior to placement in the levee section. Water may be added to the placed hydrated lime prior to mixing to reduce the dust. However, the in-place moisture content of the treated embankment material shall conform to paragraph Moisture Control. Lime shall not be mixed with the embankment materials when the soil temperature is 35 degrees F. or below, nor shall lime be applied to or mixed with frozen soils. End dumping, bottom dumping, tailgate spreading, or the use of aggregate type spreaders for spreading the lime will not be permitted. Cyclone spreaders, SECTION 31 22 23.99 15 Page 12 multi-spout spreader bars, mechanical spreaders or other types of spreaders may be used subject to the approval of the Contracting Officer. Lime shall not be applied during adverse weather conditions such as high winds and heavy rain which could cause excessive loss of the material.

3.3.2 Initial Lime Application

All embankment material in the restored levee section shall be lime treated except for the topsoil layer. The excavated materials which conform to paragraph Suitable Embankment Material shall be placed and spread to a maximum loose thickness of 10 inches. Hydrated lime shall be applied to achieve a uniform quantity of 16.0 pounds per square yard over the entire treated material stockpile area. The lime and soil shall be mixed together thoroughly with a pulverizer to a depth of 10 inches. The Contractor shall produce a workable mixture of modified soil where at least 30 percent is finer than the No. 4 (4.75-mm) U.S. standard sieve. Determination of water content shall be performed in accordance with paragraph Moisture Control and shall be required immediately after the mixing process of the initial application of hydrated lime at two (2) random locations spaced no closer than 50 feet apart for each stockpiled layer. The Contractor shall obtain sample of material to perform a standard compaction test in accordance with paragraph MATERIAL TESTING, General to determine optimum moisture content.

The Contractor shall allow the last lift in the treated stockpile to cure/mellow a minimum of 24 hours before the final lime application is placed.

3.3.3 Final Lime Application

Hydrated lime shall be applied to achieve a uniform quantity of 16.0 pounds per square yard over the entire treated material stockpile area. The lime and modified soil shall be mixed together thoroughly with a pulverizer to a depth of 10 inches. The Contractor shall produce a workable mixture of modified soil where at least 60 percent is finer than the No. 4 (4.75-mm) U.S. standard sieve. The Contractor shall remove this lift to a maximum depth of 10 inches before treating another lift with the final lime application. The Contractor shall place and compact the treated embankment material within a maximum of 8 hours after mixing in the final lime application.

3.4 LEVEE EMBANKMENT RESTORATION

3.4.1 Foundation Preparation

The excavated bottom of the slide repair area shall be kept thoroughly drained. The Contractor shall treat the excavated bottom of the slide repair area with 16.0 pounds per square yard of hydrated lime and mixed into the foundation to a depth of 10 inches which shall then be compacted as specified in paragraph Compaction prior to placing any treated embankment material. Determination of water content shall be performed in accordance with paragraph Moisture Control and shall be required immediately after the mixing process of the application of hydrated lime at two (2) random locations spaced no closer than 30 feet apart.

3.4.2 Moisture Control

The Contractor shall control the moisture of treated embankment material by either sprinkling with water or drying. The in-place moisture content shall be no more than four percent (4%) above nor minus one percent (-1%) less than the optimum moisture content as determined by testing specified

SECTION 31 22 23.99 15 Page 13 in paragraph MATERIALS TESTING, General. The Contractor shall perform the necessary work in moisture control to bring the in-place embankment material within the moisture content range specified above. If the embankment material is too wet, it shall be processed by disking and harrowing until the moisture content is reduced sufficiently. If the embankment material is too dry, it shall have sufficient moisture uniformly distributed in the treated material stockpile area.

3.4.3 Placement

The treated embankment material shall be placed and spread in lifts. The lifts shall not be more than 6 inches in thickness after compaction. Lifts shall be started full out to the slope stakes and shall be carried substantially horizontal and parallel to the levee alignment with sufficient crown or slope to provide satisfactory drainage during construction. Benching into the slope of the existing levee embankments is required in order to place and compact the material in horizontal layers.

Each lift shall be bench a minimum of twelve inches (12") into the existing levee embankment. Fill or backfill shall not be placed upon frozen ground.

3.4.4 Compaction

3.4.4.1 Requirements

Each layer of material shall be compacted to at least 95 percent (95%) of the maximum dry density as determined by the standard compaction test in paragraph MATERIALS TESTING, General. Compaction with/by the tires or treads of the hauling equipment will not be allowed, nor will compaction by saturation be allowed. Full time inspection and testing shall be performed by a commercial testing laboratory as specified in paragraph QUALITY

CONTROL.

3.4.4.2 Drain Lines and Closure Structures

Equipment producing concentrated wheel or track loads will not be allowed within 4 feet of drain lines or closure structures. The backfill shall be compacted only by hand and/or mechanically tamped within a minimum distance of four feet in all directions from the gate structure, culvert pipe or closure structure. Backfill shall be brought up to grade uniformly so as to not induce any unbalanced lateral loading on the gate structure and/or culvert pipe. Each layer of material shall be compacted to at least 95 percent of the maximum dry density as determined by the moisture density relationship determined in paragraph MATERIALS TESTING, General.

Determination of in-place density shall be in accordance with ASTM D 1556 or ASTM D 2937.

3.4.5 Replacement of Topsoil

The final 8 inches of the restored levee slopes shall be constructed of the stockpiled topsoil or untreated suitable materials and compacted with four

(4) passes of a crawler-type tractor. During the dressing or finishing operations, the restored surfaces shall be dressed smooth to match the existing, adjacent, undisturbed levee section and slopes. The establishment of turf operation shall not commence until the Contracting Officer approves the final restored levee section and grades.

3.4.6 Scarifying

Each lift surfaces shall be thoroughly broken to provide adequate bond

SECTION 31 22 23.99 15 Page 14 between lifts. If the Contracting Officer determines that during placement procedures, the lift surface is too smooth and a plane(s) of seepage or weakness result, the lift surface shall be adequately scarified before depositing material thereon. All scarifying and breaking of ground surface shall be accomplished parallel to the levee alignment.

3.5 GRADE TOLERANCES

The location, grades, dimensions, and slopes shall conform to the applicable cross sections on the drawings unless otherwise specified. A tolerance of two-tenths of one foot above the prescribed grade and cross section shown will be permitted in the final dressing. The above tolerance will be permitted provided: (1) that any excess material is so distributed such that the crown of the levee drains, (2) there are no abrupt humps or depressions in surfaces, (3) there are no bulges in the width of the crown, and (4) the side slopes are uniform. Any partial fill or temporarily stockpiled material placed within the section shall not exceed the design grade by more than one foot or have side slopes steeper than 1 Vertical on 3 Horizontal.

3.6 SURVEYING MONUMENTS

The Contractor shall install Government furnished surveying monuments on concrete columns, 12 inches in diameter by three feet deep, adjacent to the levee crown edge at each end of the slide repair. The Contractor shall permanently impress on the surveying monuments the slide number and upstream or downstream designation e.g. ME-01-08R,US. Actual slide numbers shall be as shown on the drawings. The Contractor shall install the surveying monuments and construct a concrete column in the embankment so that the monument is in the center of the concrete column and the top surface is nearly flush with the ground. The exact location of the monument will be at each end of the repaired slide as determined in the field by the Contracting Officer's Representative. The concrete shall have a minimum compressive strength, f'c = 3,000 psi at 28 days and contain 6 percent entrained air with a maximum water/cement ratio by weight of 0.50 and have a float finish. After the survey monuments have been installed the Contractor shall provide the location of each monument surveyed to the nearest 0.25'.

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SECTION 31 22 23.99 15 Page 15