Div_35.pdf

Lower Rio Grande Flood Control Project Rehabilitation of Main Floodway, From 23rd Street to FM 1015 Hidalgo County, Texas

DIVISION 35-

USIBWC Contract No.: IBM09B0005 WATERWAY AND MARINE

US INTERNATIONAL BOUNDARY & WATER COMMISSION

GOVERNING TECHNICAL SPECIFICATIONS AND PROVISIONS

DIVISION 35 – WATERWAY AND MARINE

DIVISION 35-

USIBWC Contract No.: IBM09B0005 WATERWAY AND MARINE

This Page Intentionally Blank

CONSTRUCTION OF LEVEE

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 1

SPECIFICATION 35 41 00

This specification includes requirements for the construction of a earth levee within the Work area, and includes the following:

1.1 Related Documents, Contract Clauses, & Specifications

1.2 General

1.3 References

1.4 Submittals

1.5 Access, Haul Roads, Routing, and Staging

1.6 Mapping and Filed Surveys

1.7 Sources of Fill Material

1.8 Subsurface Information

1.9 Samples Furnished to the Government

1.10 Drainage and Dewatering

1.11 Protection of Existing Features

1.12 Permits

2.1 Materials

2.2 Equipment

3.1 General Construction

3.2 Shoring, Sheeting, and Bracing

3.3 Excavation Operations

3.4 Fill Operations

3.5 Materials Testing

3.6 Contractor Quality Control

3.7 Equipment Traffic on Foundation and Fill Zones

3.8 Completed and Partially Placed Fill

4.0 Measurement and Payment

PART 1 - GENERAL

1.1 RELATED DOCUMENTS, CONTRACT CLAUSES, & SPECIFICATIONS

The following may not include all related documents, contract clauses, & technical specifications, and does not relieve the Contractor of the responsibility of performing work associated with this specification in accordance with all terms of the Contract herein.

A. Related documents: As described in paragraph 1.2 of SPECIFICATION 01 01 00.

B. Contract: Section I “Specifications and Drawings for Construction”

1.2 GENERAL

The work covered by this Specification consists of furnishing all submittals, labor, equipment, plant, materials, and all efforts necessary to perform levee construction and general earthwork as defined for this project. In regard to earthwork whether it is excavation; handling; placement; work beneath, adjacent, or above a pipe; work beneath, adjacent, or above a structure; or earthwork in general, this section shall govern if there is disagreement with or between specification sections or plan sheets.

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1.3 REFERENCES

The publications listed below form a part of this Specification to the extent referenced or where the procedure or information is necessary for performance of the work. The publications are referred to in the text by basic designation only.

ASTM D 422 (1963; R 1998) Particle-Size Analysis of Soils

ASTM D 698 (1991; R 1998) Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/cu. ft. (600 kN-m/cu. m.))

ASTM D 1140 (1997) Amount of Material in Soils Finer than the No. 200 (75-micrometer) Sieve

ASTM D 1556 (1990; R 1996) Density and Unit Weight of Soil in Place by the Sand-Cone

Method

ASTM D 2167 (1994) Density and Unit Weight of Soil in Place by the Rubber Balloon Method ASTM D 2216 (1998) Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass ASTM D 2487 (1998) Classification of Soils for Engineering Purposes (Unified Soil

Classification System)

ASTM D 2922 (1996) Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow

Depth)

ASTM D 2937 (1994) Density of Soil in Place by the Drive-Cylinder Method

ASTM D 3017 (1996) Water Content of Soil and Rock in Place by Nuclear Methods (Shallow

Depth)

ASTM D 4253 (1993; R 1996) Maximum Index Density and Unit Weight of Soils Using a

Vibratory Table

ASTM D 4254 (1991; R 1996) Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density

ASTM D 4318 (1998) Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D 4643 (1993) Determination of Water (Moisture) Content of Soil by the Microwave

Oven Method

ASTM D 5195 (1991; R 1996) Density of Soil and Rock In-Place Below the Surface by Nuclear

Methods

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1.4 SUBMITTALS

A. Plan of Operations. Fifteen (15) calendar days prior to commencement of haul road construction or placing embankment and backfill whichever is earlier, the contractor shall submit for compliance-confirmation a Plan of Operations for accomplishing all operations and for the location and construction of haul roads. Compliance-confirmation of the detailed Plan of Operations shall be obtained from the COR prior to starting the work.

B. Testing Laboratory. Compliance-confirmation of testing facilities shall be based on compliance with ASTM E548, and no work requiring testing will be permitted until the facilities have been inspected and compliance-confirmed by the COR.

C. Embankment and Backfill Materials. At least ten (10) calendar days prior to placement of any material, the Contractor shall submit to the COR the results of all required testing necessary to classify the material and necessary for determining if placement is in compliance with the requirements herein.

D. Nuclear Density Testing Equipment Operator. Nuclear density testing equipment shall be used in accordance with ASTM D 2922 and ASTM D 3017. In addition, the following condition shall apply:

(1) Prior to using the nuclear density testing equipment on the site, the Contractor shall submit to the COR a certification that the operator has completed a training course compliance-confirmed by the nuclear density testing equipment manufacturer.

(2) The nuclear density testing equipment shall be capable of extending a probe a minimum of twelve (12) inches down into a hole.

E. Reports - Survey Records. Submit a copy of the records of each compliance survey the next work day following the survey.

F. Test Results. Test results shall be furnished the COR within twenty-four (24) hours of making the test.

G. Inspection and Test Results. Inspections and test results shall be certified by a registered

Professional Civil Engineer. These certifications shall state that the tests and observations were performed by or under the direct supervision of the Engineer and that the results are representative of the materials or conditions being certified by the tests.

1.5 ACCESS, HAUL ROADS, ROUTING, AND STAGING

A. In general and as a minimum, the Contractor shall be required to maintain the access, haul roads (permanent and temporary), routing, and staging areas to prevent dust, rutting, interference with normal traffic flow, litter, and general damage or deterioration.

B. Temporary Haul Roads. Temporary haul roads shall be limited to within the project right-of-way

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 4 as shown on the plans. The Contractor shall include as part of the general Plan of Operations submittal, the layout and sequencing of the temporary haul roads. Temporary haul roads shall be detailed and constructed according to intended use and shall be maintained in good condition throughout the duration of the construction contract or until the point of construction where the use is no longer required. Temporary haul roads shall not hinder surface run-off or ditch, stream, or river discharges. At the completion of the temporary haul road use, the haul road shall be removed and the area restored to its preconstruction condition or its intended construction condition as required by this construction contract. Temporary haul roads shall not be considered a separate pay item.

C. Permanent Roads Used as Haul Roads. Permanent roads used as haul roads shall be maintained throughout the duration of use and shall be restored to the pre-construction condition or the intended construction condition.

D. Access Roads. There are eighteen (18) access roads that need to be removed and replaced upon the completion of the levee enlargement. The Contractor shall remove the access roads and stockpile the material for access road reconstruction. The Contractor will provide additional material, as needed. The roads will be constructed of suitable soil with roadway base surface layers a minimum of eight (8) inches thick or as shown on the typical sections in the plans.

1.6 MAPPING AND FIELD SURVEYS

Topographic mapping is as indicated on the plan sheets. Field surveys shall be completed as necessary and shall use the vertical and horizontal control identified within the plans.

A. Layout of Work. The Contractor shall lay out the work as indicated within the plans.

B. Verification Survey. The Contractor shall complete surveys to verify work to the lines, grades, and requirements specified. .

1.7 SOURCES OF FILL MATERIAL

A. Material Source Usage. A detailed Plan of Operations shall be submitted for COR review and compliance-confirmation addressing all aspects of material sources to include borrow operations, and required excavations. Material sources usage shall be planned to optimize available material types and ensure sufficient material for each of the defined fill zones. Proposed material usage and distribution shall be included within the Plan of Operations' submittal.

B. Alternate Material Sources Proposed by the Contractor. The Contractor may submit for review and compliance-confirmation to the COR alternate material sources. The COR will make the final determination on compliance-confirmation of alternate sources. If the Contractor elects to submit an alternate material source or sources, the Contractor shall first coordinate with the COR to obtain Contractor requirements for addressing within the submittal the engineering properties, scheduling of work, environmental regulations, and cultural regulations. An incomplete material source submittal will be grounds for disapproval. The Contractor may elect to obtain processed material, such as drainage material, and will be considered acceptable subject to meeting the

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 5 requirements of the construction documents.

1.8 SUBSURFACE INFORMATION

A. Available Subsurface Information. Complete drill and sample logs and laboratory test results are found in the “Geotechnical Engineering Services Report, United States Section, International Boundary & Water Commission, Lower Rio Grande Project – Interior Levees, Rehabilitation of Main Floodway, From 23rd Street to FM 1015, Hidalgo County, Texas, May 2009” by Professional Services Industries, Inc.” identified under 00.31.32 Geotechnical Data of the Contract Documents.

B. Use of Subsurface Information. Drill, sample, and test results are an indication of the subsurface condition at the location of the boring and tests. Variations in subsurface condition may exist between boring and test locations. Soil moisture contents and groundwater levels are indication of that information at the time of the measurement, sample extraction, and/or testing. Soil moisture content and groundwater level may vary with time in response to seasonal precipitation and river stage variations. As a result, moisture contents and groundwater levels at the time of construction may differ from the data shown on the drawings.

1.9 SAMPLES FURNISHED TO THE GOVERNMENT

Upon request from the COR and within four (4) hours of the COR request, the Contractor shall furnish samples from material sources, placed fill, ongoing construction, and/or completed construction. The specifics of sample acquisition to include method, conditions, quantity, container, and other requirements will be specified by the COR. Contractor shall perform this service at no cost to the Government.

1.10 DRAINAGE AND DEWATERING

The Contractor shall address in their general Plan of Operations the methods of drainage control. The Contractor shall maintain natural drainage patterns and/or designed drainage patterns. Temporary work, such as haul roads, shall be designed and constructed so as not to induce adverse flooding or backwater from general run-off and pipe, ditch, stream, or river discharge. The Contractor shall complete necessary efforts to divert run-off and pipe, ditch, stream, or river discharge away from excavations, fill areas, and general construction. The Contractor shall monitor and make adjustments as necessary.

1.11 PROTECTION OF EXISTING FEATURES AND ONGOING OR COMPLETED

CONSTRUCTION

A. The Contractor shall plan and conduct operations to ensure the protection of existing features and ongoing and completed construction. Damages occurring during the course of this construction contract as a result of the Contractor's actions or negligence shall be repaired by the Contractor at no expense to the Government. Analyses, designs, details associated with the repairs shall be prepared by a compliance-confirmed design firm at no expense to the Government. The Contractor shall submit the designs for COR review and shall not begin work until the design has been compliance confirmed. In some cases the repair may require an upgrade. If the upgrade is at the request of the Government, then the Contractor shall be responsible for the expense of the design in its entirety including the upgraded features. However, the Government will provide an

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 6 equitable adjustment in cost to cover the expense of the construction associated with the upgrade.

B. Notification and Coordination. When work is to be completed on an existing feature, adjacent to an existing feature, or any time work is planned that may impact an existing feature or an area activity, the Contractor shall be responsible for coordinating with impacted parties to prevent complications with disrupting service or activity.

C. Ongoing and Completed Construction. In general, the Contractor shall complete the necessary efforts to protect ongoing and completed construction. Earth fills and exposed cuts shall be protected from construction activity and general erosion. Damages occurring shall be repaired by the Contractor at no expense to the Government. The Contractor shall be responsible for protecting against general erosion and repair thereof until the cover has been placed and in the instance of vegetative cover, until the vegetation has established to the point that erosion cannot occur.

D. Public Roads, Accesses, and Appurtenances. The Contractor shall plan and complete the necessary efforts to protect public roads, accesses, and appurtenances from damages associated with this construction project. The Contractor is directed to Clause 60, "Permits and Responsibilities" of the "Construction Contract Clauses". Contractor's activities shall not deter public use of the roads, accesses, and appurtenances. At locations where public roads, accesses, and/or appurtenances are damaged or destroyed because of the work required under this contract, the Contractor shall provide temporary facilities until a permanent repair can be completed and the construction operations adjusted to prevent further damage. Temporary facilities shall be removed by the Contractor when the permanent repair is complete. Load limits on the existing roads and bridges shall be coordinated with the TxDOT or appropriate governing entity, and the Contractor shall comply with the load limits or complete compliance-confirmed modifications to allow for increased loads.

E. Environmental and Cultural. The Contractor is referred to and shall comply with the requirements of environmental protection.

F. Blasting and Explosives' Storage. Blasting shall not be allowed for this construction project.

Explosives shall not be stored on site for any reason or for any length of time.

G. Impacts Outside Construction Right of Way. Contractor's work directly or indirectly impacting property not included within the project's construction right of way limits, shall be coordinated with the COR, and proof of Contractor acquired right of way or easements of the impacted real estate or facility shall be provided to the COR thirty (30) days prior to impacting the real estate or facility.

1.12 PERMITS

For the work within this Specification, the Contractor shall be responsible for coordinating and obtaining all permits required by Federal, state, and local entities.

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PART 2 – MATERIALS & EQUIPMENT

2.1 MATERIALS

The Contractor shall furnish materials for Work under this Specification as follows:

A. Fill Materials

(1) Impervious material shall consist of fine-grained materials of low permeability consisting of clay soils. Impervious material shall be free of crushed rock, debris, plant growth, roots, and humus. The fill material shall have a maximum liquid limit of seventy-five percent (75%), a plasticity index less than or equal to forty-five percent (45%) and a minimum amount passing a US Standard No. 200 sieve of seventy-five percent (75%). Acceptable impervious material will be CL and CH as classified in accordance with ASTM D 2487.

(2) Pervious material shall consist of free draining sand, gravely sand, sandy gravel, and/or gravel. Pervious material shall be sound durable particles and shall be free of plant growth, roots, humus, debris, and deleterious substances. The particle size of pervious material shall be such that not more than five percent (5%) of the materials pass the US Standard No. 200 sieve as determined with a washed gradation test. Acceptable pervious material will be SW, SP, GW, and/or GP as classified in accordance with ASTM D 2487.

B. Drainage Material. Drainage material to facilitate seepage adjacent to pipes and structures shall consist of free draining fine to medium sand. Drainage material shall be sound durable particles and shall be free of plant growth, roots, humus, debris, and deleterious substances. The particle size shall be such that one hundred percent (100%) of the materials passes the US Standard No.

10 sieve and not more than five percent (5%) of the materials pass the US Standard No. 200 sieve as determined with a washed gradation test. Acceptable pervious material is SP as classified in accordance with ASTM D 2487.

C. Topsoil Material. In general, topsoil material shall be material organic in nature and capable of sustaining the specified vegetative growth. Topsoil material shall be the material stripped in preparation of the fill, excavation, or general construction. Stripped material is addressed within SPECIFICATION 31 14 00, "Remove / Stockpile Existing Material". Topsoil from offsite sources, proposed by the Contractor and compliance-confirmed by the COR, shall be supplemented as necessary when there is insufficient acceptable on-site sources. Topsoil material shall be free from clay lumps, weeds, litter, brush, matted roots, toxic substances, or any material harmful to plant growth or which would hinder grading, planting, operation, or maintenance operations. Topsoil material shall not contain more than five percent (5%) by volume of stones or other such objects larger than one (1) inch in any dimension. Topsoil material shall be such that a minimum of fifty percent (50%) of the soil particles pass a US Standard No. 200 sieve.

D. Cement-Stabilized Backfill. Furnish uncontaminated materials of uniform quality that meet the requirements of the plans and specifications. Notify the COR of the proposed material sources and of changes to material sources. The COR will verify that the specification requirements are met before the sources can be used. The COR may sample

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 8 and test project materials at any time before compaction. Use Tex-100-E for material definitions.

(1) Cement. Furnish hydraulic cement that meets the requirements of DMS-4600, “Hydraulic Cement,” and the Department’s Hydraulic Cement Quality Monitoring Program (HCQMP).

Sources not on the HCQMP will require testing and compliance-confirmation before use.

(2) Water. Furnish water free of industrial waste and other objectionable material.

(3) Mix Design. The COR will determine the target cement content and optimum moisture content to produce a stabilized mixture that meets the strength requirements shown on the plans. The mix will be designed in accordance with Tex-120-E or will be based on prior experience with the project materials. The Contractor may propose a mix design developed in accordance with Tex-120-E. The COR will use Tex-120-E to verify the Contractor’s proposed mix design before acceptance. Reimburse the Government for subsequent mix designs or partial designs necessitated by changes in the material or requests by the Contractor.

2.2 EQUIPMENT

A. Earthwork construction equipment intended for the tasks identified hereinafter shall comply with the requirements specified.

B. Towed Tamping Rollers. Towed tamping rollers shall be used for compaction of impervious material. Tamping rollers shall consist of a heavy duty double drum unit, with a drum diameter not less than sixty (60) inches, and an individual drum length of not less than sixty (60) inches.

The drums shall be capable of being ballasted with water or a combination of sand and water.

Each drum shall have staggered feet uniformly spaced over the cylindrical surface such as to provide approximately three (3) tamping feet for each two (2) square feet of drum surface. The tamping feet shall be seven (7) to nine (9) inches in clear projection from the cylindrical surface of the roller and shall have a face area of not less than five (5) square inches or more than seven

(7) square inches. The roller shall be equipped with cleaning fingers, so designed and attached as to prevent the accumulation of material between the tamping feet, and these cleaning fingers shall be maintained at their full length throughout the periods of use of the roller. The weight of the roller shall not be less than three thousand, five hundred (3500) pounds per foot of linear drum length weighted, and shall not be more than two thousand (2000) pounds per foot of drum length empty. The two drums comprising one (1) roller unit shall be yoked such that they will oscillate when traversing uneven surfaces. The design and operation of the tamping roller shall be subject to the compliance-confirmation of the COR who shall have the right at any time during the prosecution of the work to direct such repairs to the tamping feet, minor alterations in the roller and variations in the weight as may be found necessary to secure optimum compaction of the earth fill materials. The Contractor may be required to add ballast to the roller to the maximum capacity specified by the manufacturer of the roller. The roller shall be drawn by a crawler-type or a rubber-tired tractor at a speed not to exceed three and a half (3.5) miles per hour. The use of the rubber-tired tractor shall be discontinued if the tires leave ruts that prevent uniform compaction by the tamping roller. If tamping rollers are used in tandem, not more than two rollers

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 9 in tandem will be permitted and in such case, one (1) trip of the tandem rollers over any surface will be considered as two (2) passes. When tamping rollers are used in tandem, the tamper foot spacing shall be offset so that the circumferential rows on the rear drums are in line with the midpoint of the circumferential rows on the forward drums.

C. Self-Propelled Tamping Rollers. Self-propelled tamping rollers may be used in lieu of towed tamping rollers provided the foot pressure on the tamping feet of the self-propelled roller are approximately the same as the foot pressure on the towed roller. For self-propelled rollers steered with rubber-tired wheels, the tire pressure shall not exceed forty (40) pounds per square inch.

Self-propelled rollers shall be operated at speeds not exceeding three and a half (3.5) miles per hour. The COR has the authority to limit or eliminate the use of self-propelled rollers if they are found to cause shearing or laminations of the compacted fill.

D. Vibratory Rollers. Vibratory rollers shall be used for compacting pervious materials in random fill, drainage fill, and aggregate surfacing. Vibratory rollers shall be equipped with a smooth steel compaction drum and shall be operated at a frequency of vibration during compaction operations between eleven hundred (1100) and fifteen (1500) vibrations per minute. Vibratory rollers may be either towed or self-propelled and shall have an unsprung drum weight that is a minimum of sixty percent (60%) of the rollers' static weight. Towed rollers shall have at least ninety percent (90%) of their weight transmitted to the ground through the compaction drum when the roller is standing in a level position hitched to the towing vehicle.

E. Hand Operated Power Tampers. In areas where large equipment is not allowed or it is impracticable to use a roller, compaction shall be performed by the use of compliance-confirmed hand operated power tampers. Hand operated power tampers shall be used for compaction impervious materials and shall be capable of compacting material in a confined area. The compactors shall be either an internal combustion or pneumatic activated tamper. Tampers shall have sufficient weight and striking power to produce the specified compaction. The character and efficiency of this equipment shall be subject to the compliance-confirmation of the COR. Where hand operated equipment is used, compaction shall be a performance specification achieving the minimum compaction requirements.

F. Hand Operated Vibratory Plate. In areas where large equipment is not allowed or it is impracticable to use a vibratory roller, compaction shall be performed by the use of a compliance-confirmed hand operated vibratory plate. Hand operated vibratory plates shall be used for compaction of pervious materials and shall be capable of compacting material in a confined area.

Hand operated vibratory plates shall utilize the oscillating cam principal and shall deliver an impact of not less than two thousand (2000) pounds and be rated to deliver two thousand (2000) impulses per minute. The character and efficiency of this equipment shall be subject to the compliance-confirmation of the COR. Where hand operated equipment is used, compaction shall be a performance specification achieving the minimum compaction requirements.

G. Crawler Type Equipment. Crawler type equipment shall only be used for compaction if there is continuous successful demonstration of achieving compaction requirements. Crawler equipment shall weigh not less than twenty thousand (20,000) pounds and shall exert a unit tread pressure of

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 10 not less than six (6) pounds per square inch. Speeds shall not exceed three and a half (3.5) miles per hour.

H. Wetting Equipment. Wetting equipment shall consist of tank trucks, pressure distributors or other equipment designed to apply water uniformly and in controlled quantities and rates to variable surface widths. Wetting equipment compliance-confirmation shall be based on demonstration of satisfactory performance. Wetting equipment types and operations shall not compact or excessively wet the material to receive the moisture and shall not result in standing water within the material to be wetted or areas adjacent the staging.

I. Materials' Manipulation Equipment. Scarifiers, discs, spring-tooth or spike-tooth harrows, spreaders, and other equipment shall be suitable for use in manipulating materials in preparation of use in construction. Equipment shall be subject to compliance-confirmation by the COR and shall be based on demonstration of satisfactory performance. Equipment used for blending materials shall be capable of penetrating the full thickness or capable of processing the full thickness of the material. Satisfactory performance shall be based on consistent complete and thorough processing of the material or materials.

J. Other Earthwork Equipment. Other Equipment not mentioned such as equipment for earthwork extraction and handling shall be subject to COR compliance-confirmation, and compliance-confirmation shall be based on continued satisfactory performance. When conditions change, equipment changes may be required. The Contractor shall be made aware of conditions specific to a floodplain with a fluctuating river adjacent to the work.

The Contractor shall consider operational (or trafficability) problems such as, but not limited to, pumping of water and materials to the surface by moving equipment as well as bogging of equipment in soft, wet ground. Selection and proposal of equipment in the Plan of Operations shall account for ground conditions associated with floodplains near a fluctuating river.

K. Provide machinery, tools, and equipment necessary for proper execution of the work.

Provide proof rollers in accordance with SPECIFICATION 31 81 00, “Proof Rolling,” when required.

L. Cement Storage Facility. Store cement in closed, weatherproof containers.

M. Cement Slurry Equipment. Use slurry tanks equipped with agitation devices to slurry cement on the project or other compliance-confirmed location. The COR may approve other slurrying methods. Provide a pump for agitating the slurry when the distributor truck is not equipped with an agitator. Equip the distributor truck with a compliance-confirmed sampling device.

N. Pulverization Equipment. Provide pulverization equipment that:

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(1) cuts and pulverizes material uniformly to the proper depth with cutters that will plane to a uniform surface over the entire width of the cut;

(2) provides a visible indication of the depth of cut at all times; and,

(3) uniformly mixes the materials.

PART 3 – CONSTRUCTION METHODS

3.1 GENERAL CONSTRUCTION

A. All work shall be in compliance with the requirements of the construction documents including compliance-confirmed submittals.

B. Dewatering and Run-off Control. Where dewatering and/or run-off control is necessary, the

Contractor shall submit all design and plans for COR review. Surface and groundwater control shall be accomplished as necessary in coordination with the required excavation and embankment construction. Run-off control shall also include control of discharges from pipes either currently discharging or discharging as a result of being severed. Surface water and/or groundwater control may necessitate the use of temporary diversion ditches, cofferdams, and/or pumping from wells, well points, and/or sumps.

3.2 SHORING, SHEETING, AND BRACING

A. Where excavation or fill support is necessary to support earth, protect adjacent features, or maintain worker safety, the support system shall be designed in accordance with Standard levee criteria and submitted for COR compliance-confirmation. Design shall be completed by a registered professional engineer with experience in this kind of work. Shoring, sheeting and bracing shall not be used in lieu of the required excavation slopes where there is sufficient space for cut back slopes. The design and submittal shall also address removal of the excavation or fill support. All shoring, sheeting and bracing shall be removed as embankment and backfill operations progress and the void filled by a COR compliance-confirmed method.

B. Free Board Gages. Free board gages shall be constructed if required by the COR.

C. Moisture Content Adjustment --General. The Contractor shall develop a plan for adjusting moisture contents of the available fill material to achieve the proper placement and compaction.

Moisture contents for impervious material may require air drying or additives for moisture content reduction or sprinkling and mixing to increase the moisture content. Contractor may propose alternative methods to adjust moisture contents. The submittal shall include in detail the planned procedures. Adjustment of moisture content shall not be an added expense to the Government.

D. Moisture Content Adjustment--Air Dry. The Contractor may reduce the moisture content by staging operations to allow spreading of material and disking the soil to expose it to air and sun.

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The submittal shall address such tasks as efforts to acquire the wet material from the borrow area, borrow sequencing, location of spreading, procedure to avoid crusting of the spread soil or exposed borrow, plan to avoid introduction of moisture from rainfall, continuous aeration, seasonal complications, and transfer of material to the fill zone. The submittal shall also address in detail staging, equipment, and anticipated results.

E. Moisture Content Adjustment--Admixtures. The Contractor may reduce the moisture content by mixing additives within the wet soil. The submittal shall address in detail as a minimum the procedure, equipment, mixture, and case studies where used before (under similar circumstances).

Applicable requirements considered within the air dry option shall also be included within this submittal. The use of fly ash or other drying agents, compliance-confirmed by the COR, may be proposed by the Contractor. The submittal shall also include moisture-density curves developed for the material types and admixture percentage. The moisture-density curve for the fill with the admixture (drying agent) shall be used to establish the maximum dry density and optimum moisture content for the fill type with the drying agent incorporated. Adjustments in the drying agent will constitute a different fill material type and will be subjected to the required testing.

3.3 EXCAVATION OPERATIONS

A. Excavation shall consist of removal to the lines and grades shown on the plan sheets and as directed herein and the handling to include stockpiling, loading, hauling, and/or placement as required. Excavations shall be maintained free of debris of any sort or deposited material.

Excavations shall be protected from surface runoff. Excavation drainage and dewatering shall be coordinated as required by these construction documents to include compliance-confirmed submittals. Excavation shall not be initiated until utilities have been cleared.

B. Clearing, grubbing, and stripping shall conform to SPECIFICATIONS 31 11 00 and 31 14 00.

C. Excavation for Structures and Pipes. Excavations for structures shall conform to the dimensions and elevations indicated for each structure, except as specified hereinafter, and shall include trenching for utility and foundation drainage systems. Excavation shall extend a sufficient distance from walls and footings to allow for placing and removal of forms. Satisfactory material removed below the depths indicated without specific direction of the CO shall be replaced at no additional cost to the Government and filled in accordance with the requirements herein. Over excavation below required invert elevations or bottoms of footings shall be backfilled with satisfactory material compacted to the density of the surrounding undisturbed material at no additional cost to the Government. No footings shall be constructed on unsatisfactory material as determined by the COR. Excessively wet and/or soft material in subgrades resulting from water ponding in footing excavations shall be removed and replaced with satisfactory material compacted to the density of the surrounding undisturbed material.

D. Excavations for Relocations. Pipe placement shall be completed such that the fill is placed to an elevation and then shaped for the pipe diameter such that sixty percent (60%) of the horizontal pipe diameter is bedded into the shaped fill. The practice may be labor intensive especially when occurring in impervious materials. The Contractor shall demonstrate satisfactory completion.

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Shaped fill and pipe placement shall be inspected by the COR prior to continued backfill operations. Additional shaping shall be required where irregularities occur such as pipe joints and connections.

E. Excavation for Ditching. Excavation for drainage ditches shall be to the layout, lines, and grades shown in the plan sheets or as directed herein.

F. Excavation Slopes and Surcharges. Excavation slopes shall be to the grades shown on the plan sheets or as directed herein. Under no circumstances, temporary or permanent, shall the slopes be steeper than the slopes required.

G. Over Excavations.

(1) Over Excavations Outside the Limits of the Levee. Over excavation outside the limits of the foundation of the levee (or structure or pipe within the levee alignment) shall be backfilled to grade with similar materials or a COR compliance-confirmed alternate material and compacted to a density of at least that of the surrounding undisturbed material or if an alternate material is compliance-confirmed, to the density required for that material type.

(2) Over Excavations Within the Limits of the Levee. Over excavation within the limits of the foundation of the levee (or structure or pipe within the levee alignment) shall be backfilled to grade with impervious material in accordance with the compaction requirements herein.

H. Excavation Tolerances. A tolerance of six (6) inches above or below the prescribed grade will be allowed in the excavation for ditches, inspection trenches. Excavation tolerances shall not be allowed where excavation is for a structure or pipe.

I. Stockpiles for Excavated Material. Where excavated material is to be used for fill of the construction of this project, the Contractor shall either place and compact, as the material is being excavated, or stockpile the material until ready for use. Stockpiled material shall be placed such that any part of the stockpile is no closer to the excavation than a distance equal to the depth of the excavation. Stockpiled material placed the minimum distance from the excavation shall not be higher than the adjacent excavation depth and shall maintain the slope of the excavation. The slope of stockpiled material placed a stable distance from the excavation as compliance-confirmed by the COR shall be no steeper than. Stockpiles shall be protected from contamination of differing materials, natural occurrences, and general construction activities.

3.4 FILL OPERATIONS

A. In general, fill operations shall conform to the requirements herein these construction documents and compliance-confirmed submittals. The methodology shall primarily be a procedural specification with specific material properties maintained within a specified range or limit.

However, specified testing shall be required to verify the specified ranges or limits are met and to verify adequacy of the procedure. If the specified ranges and limits are met and the procedure doesn't deliver the defined compaction results, then an adjustment in the procedure may be

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 14 specified and an equitable adjustment made in the price to the Contractor or in lieu of this, the COR may adjust the compaction values. If the specified ranges and limits and/or procedure are not met, then the Contractor shall adjust the operations for compliance and the fill reworked at no additional cost to the Government.

B. Limits of Fill Operations. Fill shall be placed to the lines and grades and within the appropriate fill zone as indicated within the plans and as stated herein this section. Only compliance-confirmed materials as defined herein shall be placed in the appropriate fill zones. Topsoil shall be placed within the fill lines indicated on the plan sheets per the requirements herein.

Unsatisfactory materials shall be the responsibility of the Contractor for disposition. The Contractor shall place fill in such a manner as to prevent mixing of material types especially at the fill zones' interfaces.

C. Surface Preparation for Fill Placement. Clearing, grubbing, stripping, and/or general excavation shall be completed as required prior to any fill operations. If any tree or deep-rooted vegetation removal is required along the levee alignment, the entire root ball shall be completely removed by the Contractor. Any resulting holes should be backfilled using clay fill, placed and compacted.

The existing caliche / base layer on top of the levee shall be completely removed prior to the placement of subsequent embankment clay fill. Fill shall not be placed on the embankment foundation until the area to receive the fill has been inspected and compliance-confirmed by the COR. Surfaces subjected to fill to include prepared ground surface and the previous placed lift shall be moisture-conditioned by scarifying to a minimum depth of six (6) inches and re-compacting to a minimum of ninety-five percent (95%) of the maximum dry density as determined from ASTM D698. Scarified surfaces compacted prior to placement of the subsequent lift shall be re-scarified. The moisture content of the subgrade should be maintained within the range of optimum moisture content to three (3) percentage points above the optimum moisture content until permanently covered. Fill shall be placed in layers and compacted in accordance with the provisions for the specific material type required herein. Where necessary the moisture content shall be adjusted for the scarified soil or the fill to be placed. Surfaces shall be graded to drain.

D. Proof Rolling and Grubbed Areas. Once a site is cleared, grubbed, stripped, and/or excavated, the site shall be proof rolled to locate loose, saturated, or soft zones. Loose and soft zones shall be removed and disposed. Cuts such as grubbed areas or topography that is abrupt with steepened sides shall be excavated to flatten the steepened sides. Surfaces subjected to fill shall be thoroughly scarified prior to placing fill.

E. Removal of Unsatisfactory Materials. Prior to placement of fill, materials within the surface to receive fill that do not meet the material requirements as specified herein or have been subjected to conditions such as saturating rain or freeze conditions, shall be removed prior to placement of fill.

F. Benching. When fill is to be placed against an embankment such as the existing levee, the

Contractor shall bench into the embankment to facilitate fill placement. The vertical face of the bench shall be approximately the compacted lift thickness of the adjacent fill.

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 15

G. Placement of Fill. In general, placement of fill shall be in accordance with the requirements of the specifications and to the lines and grades shown on the drawings. Where vegetative cover is scheduled, topsoil shall be placed within the limits of the lines and grades of the plan sheets but not to exceed the specified topsoil fill thickness indicated hereinafter. The Contractor shall note zone call outs in the drawings for specific material types and shall have topsoil within the finish fill lines where vegetative cover is scheduled.

H. Levee Random Fill Variation. In general, when varying compliance-confirmed material types are placed within a levee embankment fill zone, the fill shall be placed as a spectrum with the least pervious at the river-ward extent of the fill zone and the most pervious at the landward extent of the fill zone. Placement practices throughout each fill zone of the levee shall be such that the embankment will be free from lenses, pockets, streaks, and layers of material differing substantially in texture, gradation, or classification from surrounding material of the same material type. If within the same material type lenses, pockets, streaks, or layers are encountered, the Contractor shall spread and mix the materials by a COR compliance-confirmed method in order to form a blend of the materials.

I. Fill Tolerances. Fill areas shall be constructed to the grades, lines, and cross sections shown on the plan sheets and as directed herein.

J. Drainage Material. Drainage material to be placed in the fill zone adjacent to a pipe or structure to facilitate controlled seepage shall be placed and spread in a layer not more than a 6 inch loose lift thickness. Drainage material shall be placed to ensure complete placement and compaction below, adjacent, and above the pipe or structure.

K. Random Material. Random material to be placed in a random fill zone shall be placed in accordance to the material the random is comprised of impervious or pervious.

L. Topsoil Material. Topsoil material to be placed within the outer face of the appropriate fill surface and shall be 6 inches placed to the finish grade shown on the plan sheets. Topsoil shall only be placed where vegetative cover is scheduled. Topsoil shall not be placed in more than an 8 inch loose lift thickness.

M. Fill Placement Adjacent to a Structure or Pipe. Fill shall not be placed on or against concrete less than seven (7) days after concrete placement or when the concrete is less than seventy percent (70%) of the design strength. Crawler-type tractors, vibratory equipment and other similar compaction equipment shall not be used within four (4) feet of any completed or partially completed structure or pipe. Compaction within four (4) feet of completed or partially completed structures and pipes shall be accomplished by the use of mechanical hand tampers, vibrating plates, or other compliance-confirmed methods and equipment. The Contractor shall ensure that compaction operations do not damage any existing utility, structure, or pipe. Any damage caused by the Contractor's operation shall be repaired at no additional cost to the Government.

N. Compaction Requirements. In general, compaction shall be a procedural requirement with testing

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 16 requirements for verification and field adjustments. In some instances, compaction requirements shall be an end product thus producing a specified minimum density. An example is, required minimum densities specified shall be achieved for compaction below, adjacent, and above a pipe or structure regardless of compaction procedure.

O. Cement Stabilized Backfill. Construct each layer uniformly, free of loose or segregated areas and with the required density and moisture content. Provide a smooth surface that conforms to the typical sections, lines, and grades shown on the plans or as directed.

(1) Preparation of Subgrade or Existing Base for Treatment. Before treating, remove existing roadway material in accordance with pertinent bid items and the plans or as directed. Shape existing material in accordance with applicable bid items to conform to the typical sections shown on the plans and as directed. Proof roll the roadbed in accordance with SPECIFICATION 31 81 00, “Proof Rolling,” before pulverizing or scarifying existing material. Correct soft spots as directed.

(2) Pulverization. Pulverize or scarify existing material after shaping so that one hundred percent (100%) passes a two and one-half (2-1/2)-inch sieve. If the material cannot be uniformly processed to the required depth in a single pass, excavate and windrow the material to expose a secondary grade to achieve processing to plan depth.

(3) Application of Cement. Uniformly apply cement using dry placement unless otherwise shown on the plans. Add cement at the percentage determined in “Mix Design” herein.

Apply cement only on an area where mixing, compacting, and finishing can be completed during the same working day. Start cement application only when the air temperature is at least thirty-five degrees Fahrenheit (35°F) and rising or is at least forty degrees Fahrenheit (40°F). The temperature will be taken in the shade and away from artificial heat. Suspend application when the COR determines that weather conditions are unsuitable.

(a) Dry Placement. Before applying cement, bring the prepared backfill to approximately optimum moisture content. When necessary, sprinkle water as directed by the COR Distribute the required quantity of dry cement with compliance-confirmed equipment.

Minimize dust and scattering of cement by wind. Do not apply cement when wind conditions, in the opinion of the COR, cause blowing cement to become dangerous to traffic or objectionable to adjacent property owners.

(b) Slurry Placement. Mix the required quantity of cement with water, as compliance-confirmed. Provide slurry free of objectionable materials and with a uniform consistency that can be easily applied. Agitate the slurry continuously. Apply slurry within two

(2) hours of adding water and when the roadway is at a moisture content drier than optimum. Distribute slurry uniformly by making successive passes over a measured section of the roadway until the specified cement content is reached.

(4) Mixing. Thoroughly mix the material and cement using compliance-confirmed equipment.

Mix until a homogeneous mixture is obtained. Sprinkle the treated materials during the mixing operation, as directed, to maintain optimum mixing moisture. Spread and shape the completed mixture in a uniform layer. After mixing, the COR will sample the mixture at

USIBWC Contract No.: IBM09B0005 Page 35.41.00 - 17 roadway moisture and test in accordance with Tex-101-E, Part III, to determine compliance with the gradation requirements in Table 1.

Table 1

Gradation Requirements Minimum % Passing Sieve Size Base Subgrade 1-3/4 in. 100 100 3/4 in. 85 85 No. 4 – 60

(5) Compaction. Compact the mixture in one lift using density control unless otherwise shown on the plans. Complete compaction within 2 hours after the application of cement. Sprinkle or aerate the treated material to adjust the moisture content during compaction so that it is within two (2) percentage points of optimum as determined by Tex-120-E. Determine the moisture content of the mixture at the beginning and during compaction in accordance with Tex-103-E. Adjust operations as required. Begin rolling longitudinally at the sides and proceed towards the center, overlapping on successive trips by at least one-half (1/2) the width of the roller unit. Offset alternate trips of the roller. Operate rollers at a speed between two (2) and six (6) miles per hour, as directed. Remove areas that lose required stability, compaction, or finish. Replace with cement-treated mixture at the Contractor’s expense.

(a) Ordinary Compaction. Roll with compliance-confirmed compaction equipment, as directed.