539TRENCH DRAINS

422

Grate retaining devices shall not obstruct the flow of water into the channel or through the channel. A grate shall fit into the frame without rocking. It shall be held in place by stainless steel tamper resistant locking devices. The Contractor shall submit results from an independent laboratory verifying that the grates will withstand a minimum repetitive pullout resistance of 200 pounds per foot {5 kN per meter} after the completion of 1,000 hours of salt spray in conformance with ASTM B 117. The grate retaining device shall withstand, without maintenance, cyclic vertical loads of 500 pounds {2.2 kN}. Frames shall be independent of the channel and shall be anchored into the surrounding concrete by metal extensions attached to the frame at all four corners. Rails that are cast into the concrete shall be ASTM A 36 structural steel, post fabrication galvanized per ASTM A 123.

Prefabricated drain channels shall be made from components that are anchored by the placement of concrete to encase the anchoring lugs that are integral to the channel components. The physical properties of the prefabricated drain channel shall be compatible with the physical properties of the concrete. The thermal coefficient of expansion shall be similar to that of the concrete so that separation does not occur between the prefabricated drain channel and the encasement concrete. Prefabricated drain channels shall interlock with adjoining channels.

539.03Construction Requirements

The Contractor shall submit the trench drain manufacturer’s recommendations for installation to the Engineer prior to beginning installation. This submittal shall include a quantity listing of all materials required for the construction of the trench drain. The submittal shall be delivered to the Engineer at least ten calendar days prior to beginning the construction of the trench drain. The Contractor shall resubmit the trench drain data if the submittal is determined to be inadequate. Construction shall not begin until the submittal is complete. A representative of the trench drain manufacturer shall be present to advise the Engineer of the adequacy of the first trench drain units that are installed. The installation of the trench drain units shall not begin until the manufacturer's representative is present at the site of installation. Connection to an existing structure may require the use of a transitional fitting and/or sections of pipe to provide a suitable connection without damage to the grate, drain and structure. Connections to structures shall be approved by the Engineer prior to construction. When the trench drain begins or terminates without a connection to other pipes or drainage structures, the trench drain end shall be sealed or plugged with a suitable cap as shown on the plans. The seal shall provide a waterproof connection.

Excavation shall be kept as nearly as possible to the minimum width, depth, and length shown on the plans.

Precast drains shall be installed to the lines and grades shown on the plans or as directed by the Engineer. The trench slot shall be protected during installation by a removable wood strip, heavy duty tape, or other suitable material, affixed to the slot to prevent infiltration of material into the drain. After finishing the surface, the protective covering shall be removed and any debris that entered the trench shall be removed.

The furnishing and placement of the concrete shall be in accordance with the requirements given in Section 501. The prefabricated trench drain components shall be supported or held in place in such a manner as to permit flow of the concrete backfill material around the drain. The concrete encasement adjacent and beneath the drain channel shall be a minimum thickness of 6 inches (150 mm}. Drain channels shall be positioned in the excavated trench so that, when finished, the surrounding concrete backfill will encase the channel. MICRO PILES 423

Concrete backfill shall be placed in the trench against undisturbed material at the sides and bottom of the trench and in a manner that will prevent floating or shifting of the trench drain components and voids in, or segregation of, the concrete. Where necessary, earth plugs shall be constructed and compacted at the ends of the planned concrete backfill to contain the concrete within the trench. Concrete shall be finished flush with adjacent surfacing. The surface of the concrete shall be textured with a broom or burlap drag to produce a durable skid-resistant surface. Under no circumstances shall any portion of the trench drain slot extend above the paving material or curb and gutter section.

539.04Method of Measurement

The trench drain will be measured in linear feet {meters} along the top of the drain. Connections to other structures (i.e. elbows, pipe, joints, etc.) will not be measured for payment unless shown otherwise on the plans. Excavation and backfill will not be measured for payment.

539.05Basis of Payment

Trench Drain will be paid for at the contract unit price, which shall be full compensation for fabricating, furnishing and installing the trench drain components. It shall also be full compensation for furnishing and installing connections to other structures, for all concrete, excavation, backfill, satisfactory disposal of surplus materials, and for all equipment, tools, labor, and incidentals necessary to complete the work.

539-A ___ inch {mm} Trench Drain - per linear foot {meter} MICRO PILES

546.01Description

This Section shall cover the work of constructing, furnishing, and installing micro piles as shown on the contract plans, approved working drawings, and as specified herein. The Contractor shall be responsible for furnishing all design, materials, products, accessories, tools, equipment, services, transportation, labor and supervision, and manufacturing techniques required for design, installation, and testing of micro piles and top attachments. The Contractor shall select micro pile type, size, micro pile top attachment, and construction methods. The Contractor shall estimate the ground to grout bond value and determine the required bond length. The Contractor shall install a system that will provide the load capacities shown in the working drawings.

546.02Materials

Handling, storage, and control of materials shall comply with appropriate portions of Section 106. All materials shall conform to the requirements set forth in Division 800, Materials. Specific reference is made to applicable portions of the Specifications: Article 807.01 – Water

Cement shall be Type I, Type II, Type IL, Type IP, or Type IS and shall meet the requirements of Section 815.

Reinforcing steel shall be Grade 75, and shall meet the requirements given in AASHTO M31 and Section 835. Bars shall be threaded a minimum of six inches or continuous spiral deformed bars designed for coupling. Bar couplers, if required shall develop the ultimate tensile strength of the bars without any evidence of failure.

Permanent steel casting/pipe shall meet the tensile requirements of American Petroleum Institute (API) N80 as used in the design submittal, having the diameter and minimum wall thickness MICRO PILES 424

shown in the working drawings. Micro pile casing shall be smooth, non-corrugated, clean, watertight steel, and threaded to develop the required design strength of the casing section. Welded splices will not be allowed. Casings shall be new the use of used casings will not be allowed. The Contractor shall provide documentation stating the origin in accordance with the requirements given in Subarticle 106.01(a), pipe description, and quantity of pipe/casing delivered to the project. Additionally, the Contractor shall submit a minimum of two representative coupon tests from an independent testing laboratory or mill certifications, for each load of pipe/casing delivered for use on the project.

Structural steel plates and shapes for micro pile top attachments shall conform to ASTM A36 or ASTM A572 Grade 50 and Section 836.

Centralizers shall be installed to align the reinforcing bars in the micro pile. Centralizers shall be manufactured from Schedule 40 PVC pipe, steel or other material that will not be detrimental to the performance of the micro pile. The use of wood centralizers will not be allowed. Centralizers shall have a means for being securely attached to the reinforcing bar. The centralizers shall be sized to position the reinforcing bar within 1 inch of the center of the micro pile to allow tremie pipe insertion to the bottom of the micro pile and to allow free flow of grout.

The grout shall be a neat cement or sand/cement grout. The Contractor shall submit the proposed grout mix design to the Materials and Tests Engineer for approval no later than 30 calendar days prior to production. The Contractor shall make arrangements for an ALDOT approved testing laboratory to test the proposed grout mix design. The mix design shall include the following:

indicated.

minimum compressive strength of 2000 psi at 3 days, and a minimum compressive strength of 4000 psi at 28 days. Compressive strength shall be tested in accordance with the requirements given in AASHTO T 106, "Compressive Strength of Hydraulic Cement Mortar (Using 50 mm or 2 inch Specimens)". Test results for the proposed grout mix that have been completed within one year of the start of work, and that have been performed by an ALDOT approved testing laboratory, may be submitted for verification of the mix design.

546.03Micro pile Design and Submittals

The micro pile Contractor shall be experienced in the design, construction, and load testing of micro piles and have at least five years of experience and constructed at least three projects of similar size and capacity to those required by this project. The Contractor shall have previous micro pile drilling and grouting experience in soil/rock similar to project conditions. The Contractor shall submit construction details, structural details and load test results for at least three previous successful micro pile load tests from different projects of similar scope to this project. The Contractor shall assign a supervising project manager with experience on at least three projects of similar scope to this project completed over the past five years to supervise the work performed. The Contractor shall not use consultants or manufacturers’ representatives to satisfy the supervising manager requirements of this Section. The on-site foremen and drill rig operators shall also have experience on at least three projects over the past five years installing micro piles/pre-bored pile retaining wall structures.

The micro piles shall be designed in accordance with the guidelines given in FHWA NHI-05-039 “Micro pile Design and Construction Reference Manual”, by a Professional Engineer licensed in the State of Alabama, with experience in the design of at least three successfully completed micro pile projects over the past five years. The overall length of a micro pile will be selected such that the required capacity is developed by skin friction between grout and rock socket over a suitable c o n t i n u o u s length MICRO PILES 425

in competent rock. A factor of safety of 2.0 shall be used when calculating the allowable geotechnical capacity of the bond zone. The micro pile top attachment shall effectively distribute the design load to the concrete footing such that the concrete bearing stress does not exceed A m e r i c a n C o n c r e t e I n s t i t u t e ( A C I ) Building Code and the bending stress in the steel plates does not exceed American Institute of Steel Construction (AISC) allowable stresses for steel members. The geotechnical capacity shall not rely on bond from clay soils or fractured weathered rock layers, intermittent rock layers with clay seams, rock underlain by voids or boulders above the competent rock. The Contractor may independently conduct any geotechnical investigation necessary to provide a proper design and installation of the system. Any additional investigation needed during construction to define foundation conditions will be at no additional cost to the Department. If a manmade obstruction is encountered during installation of a micro pile that prevents the advancing of the micro pile; the micro pile shall be abandoned and filled with grout. The Contractor and ALDOT shall determine an acceptable alternative plan. Contractor shall be paid for abandoned holes that are due to no fault of the Contractor.

At least 30 calendar days before the planned start of micro pile construction, the Contractor shall submit 5 copies of the completed project reference list and a personnel list. The project reference list shall include a brief project description with the owner’s name and current phone number and load test reports. The personnel list shall identify the micro pile system design engineer (if applicable), supervising project manager, drill rig operators, and on- site foremen to be assigned to the project. The personnel list shall contain a summary of each individual’s experience and be complete enough for the Engineer to determine whether each individual satisfies the required qualifications. The Engineer will approve or reject the Contractor’s qualifications within 15 calendar days after receipt of a complete submission. Additional time required due to incomplete or unacceptable submittals will not be cause for time extension or impact or delay claims. All costs associated with incomplete or unacceptable submittals shall be borne by the Contractor. Work shall not be started, nor materials ordered, until the Engineer’s written approval of the Contractor’s experience qualifications is given. The Engineer may suspend the work if the Contractor uses non-approved personnel. If work is suspended, the Contractor shall be fully liable for all resulting costs and no adjustment in contract time will result from the suspension.

The Contractor shall submit working drawings and relevant structural design calculations for the micro pile system to the Bridge Engineer for review prior to the start of any work. A Registered Professional Engineer in the State of Alabama shall stamp the submittal. The following information shall be included with the working drawings and design calculations submittal(s):  A written summary report which describes the overall micro pile design.  Micro pile details for each micro pile type (load) showing: o Micro pile design load. o Elevation view showing type and size of permanent casing and reinforcing steel, o Minimum total bond length o Total micro pile length. o Micro pile top attachment.  Micro pile numbering system for records.  Grouting plan and grout mix designs, including: o Procedure for placing the grout, and methods for accurately monitoring and recording the grout depth and grout volume. o The Contractor shall clearly identify the minimum specified grout compressive strength at which load tests shall be performed. o Estimated curing time for grout to achieve specified strength. MICRO PILES 426

o Procedure and equipment for Contractor’s monitoring of grout quality and volume installed.  Detailed, step-by-step description of the construction procedure and sequence, including personnel and a quality control plan. This step-by-step procedure shall be shown on the working drawings in sufficient detail to allow monitoring of the construction and quality of the micro piles.  Information on headroom and space requirements for installation equipment that verify that the proposed equipment can perform at the site.  Details for plumb hole drilling.  Details for centralizers.  Pipe and reinforcement splice type and locations.  Details of the load testing apparatus for verification and proof loading tests.  Calibration documentation of the hydraulic jack(s) to be used for load testing.  Details for exploratory drilling of micro piles with rock sockets The Engineer will review the design calculations, working drawings, and material requirements, and construction procedure for conformance to the plans and specifications. The Engineer will not approve these parts of the submittal but will review them to ensure that they are sufficiently complete to allow the construction of the micro piles. The Engineer will return the submittal for corrections, distribute the submittal for construction inspection, or contact the Contractor to establish a mutually agreeable date and time for a meeting to discuss the submittal. The Contractor will be notified of changes in the submittal deemed necessary within seven days after the meeting. Micro pile construction shall not begin until the submittal has been distributed for construction inspection and the Engineer informs the Contractor in writing that the proposed working drawings, design calculations, material requirements, and micro pile construction procedure are complete. Distribution of the submittal for construction inspection shall not relieve the Contractor of the responsibility to satisfactorily complete the work as detailed on the plans and in the specifications. Any proposed modification of the construction procedure during construction shall be submitted to the Bridge Engineer for review and distribution.

The Contractor shall review the available subsurface information and visit the site to assess the site conditions, equipment access conditions, and location of the existing structures and above ground facilities. The Contractor is responsible for field locating and verifying the location of all utilities shown on the plans prior to beginning any work. The Contractor shall not interrupt any existing utility services unless authorized in writing. The Contractor shall notify the appropriate parties of any utility locations different from those on the provided plans that may require modification to the micro pile locations or design modifications.

A pre-construction meeting will be scheduled by the Engineer and held prior to the start of micro pile construction. The Engineer, Geotechnical Engineer, Area Materials Engineer, Bridge Engineer, Construction Engineer, prime Contractor, micro pile specialty Contractor, micro pile design engineer, excavation Contractor and geotechnical instrumentation specialist (if applicable) shall attend the meeting. Attendance is mandatory. The pre-construction meeting will be conducted to clarify the construction requirements for the work, to coordinate the construction schedule and activities, and to identify contractual relationships and delineation of responsibilities amongst the prime Contractor and the various Subcontractors—specifically those pertaining to excavation for micro pile structures, anticipated subsurface conditions, micro pile installation and testing, micro pile structure survey control and site drainage control.

546.04Construction Requirements

The contractor shall install the micro pile using core drilling, rotary drilling, percussion drilling, auger drilling, driven casing or other acceptable means unless otherwise directed. Micro piles can be installed in the drilled hole after drilling or can be advanced by the drill. MICRO PILES 427

When the micro piles design capacity is developed from a rock socket, the contractor shall perform exploratory drilling or probing to determine the location, extent, and quality of the rock in which the socket will be constructed. A minimum of 30% of the micro pile locations in each footing shall be drilled or probed. The drilling/probing locations shall be selected such that three (3) subsurface profiles are generated transverse to the long dimension of the footing and two (2) subsurface profiles are generated transverse to the short dimension of the footing. The drilling or probing shall extend into competent rock a minimum of 1.5 times the length of the proposed micro pile design rock socket. Production micro pile drilling and installation for a given footing shall not begin until the results of this exploration are submitted and approved by the Engineer. This submittal shall include the following:  A plan view showing all micro piles in the footing with corresponding micro pile numbers and locations of exploratory borings.  Drill logs indicating the existing ground elevation at the time of drilling, micro pile number, bottom of footing elevation, elevations of soil and rock layers, estimate of rock quality, and proposed micro pile tip elevations. Subsurface information contained in the contract plans may be used in lieu of exploratory drilling for individual micro piles with prior approval of the Materials and Tests Engineer.

All foreign material dislodged or drawn into the hole during construction of the micro piles shall be removed. Centralizers shall be used when installing central bar reinforcement. The contractor shall allow free flow of the grout and provide a positive means of support for maintaining the position of the casing and reinforcement until the grout has set. Reinforcement shall be lowered in the stabilized hole. Reinforcement shall not be forced or driven into the hole. The Contractor shall dispose of cuttings, construction debris, and spilled or wasted grout in accordance with the Plans and federal, state and local laws. The grout shall be mixed to produce a uniform mixture free of lumps and undispersed cement. The grout pump shall be equipped with a pressure gauge to monitor grout pressures. Provide a pressure gauge capable of measuring pressure of at least 150 psi or twice the actual grout pressures used, whichever is greater. Use grouting equipment capable of pumping the grout in one continuous operation. Continuously agitate the mixed grout during pumping operations. The grout shall be injected from the lowest point of the drilled borehole and filled without voids to the top of the micro pile. The grout may be pumped through grout tubes, casing, hollow-stem-augers or drill rods. The quantity of the grout and the grout pressures shall be recorded. The contractor shall control the grout pressures to prevent excessive heave but shall fill the entire micro pile with grout. Grout test specimens shall be made on production grout to ensure that the grout meets the requirements of Subarticle 546.02(g). The grout test specimens shall be molded and tested in accordance with the requirements given in AASHTO T 106. The Contractor’s testing technicians shall clearly label each grout cube test specimen and identify the micro piles associated/represented by each set of specimens. A set of tests specimens is comprised of three grout cubes. The requirements for grout testing are as follows:

If small batch grouting operations are used a minimum of three sets of grout test specimens shall be created for each batch of micro pile grout produced. One set of test specimens shall be designated for three-day compressive strength testing and one set shall be designated for 28-day compressive strength testing. One set of test specimens shall be given to the Engineer for transport to the Department Laboratory for verification testing.

If continuous grouting operations are used a minimum of three sets of grout test specimens shall be created for every 30 cubic yards or portion thereof of micro pile grout produced One set of test specimens shall be designated for three-day compressive strength testing and one set shall be designated for 28-day compressive strength testing. One set of test specimens shall be given to the Engineer for transport to the Department Laboratory for verification testing. MICRO PILES 428

The Department will perform random verification testing for 28-day compressive strength on a frequency of one test for every 5 batches for batch grouting operations or one test for every 150 cubic yards or fraction thereof for continuous grouting operations. The test verification sample will be selected as outlined in ALDOT-210 “Selecting Samples By The Random Numbers Method”. The Department will test the remaining four samples in the event of a low break.

The Contractor shall maintain an independent record of all field installation activities. An ALDOT Representative shall also maintain an independent record of all field installation activities. At the end of each day; the Contractor and the ALDOT Representative shall reconcile and agree upon the quantities installed. A log for each micro pile shall be created and signed by a representative of the Contractor and ALDOT. The micro pile records shall be submitted to the Project Manager within 48 hours after installation is completed for each micro pile. The records shall include the following information:  Micro pile drilling duration.  Final tip elevation.  Total micro pile length.  Description of unusual installation behavior or conditions.  Grout quantities pumped.  Grout test specimen compressive strength results.  Micro pile materials and dimensions. Post construction records shall be submitted to the Project Manager within 30 calendar days after completion of work and shall include the following:  As-built drawing showing locations of the micro piles and length.  Detailed drilling records.  Grouting records indicating the cement type and quantity injected.

The Contractor shall perform both load capacity verification testing prior to the installation of production micro piles and proof load testing of designated production micro piles. Proof load tests shall be performed on production micro piles at locations selected by the Project Manager. No load tests shall be performed before the grout has reached the minimum specified compressive strength. All load tests shall be performed with a jack calibrated in accordance with ALDOT-358 and Subitem

505.03(g)1d

The contractor shall install a minimum of one (1) non-production test pile for performance verification load testing outside of the proposed footing at the location shown on the plans or as designated by the Engineer. The test pile shall not be a production pile. The test pile shall be loaded to 200 percent the design load and evaluate the ultimate pile capacity to ensure compliance with job performance requirements. The Contractor shall notify the Engineer one week before installing test micro pile groups that are to be performance tested. No micro pile, test pile or production piles shall be load tested until three days after grouting operations are complete. Load tests shall be performed in accordance with ASTM D1143, “Standard Test Methods for Deep Foundations Under Static Axial Compressive Load”, using Procedure A – Quick Test. The axial compressive load shall be applied with a calibrated hydraulic jack. Apply the test load in increments of 5% of the anticipated failure load to maximum of a 200 percent of the foundation load shown on the Bridge Layout. Add load increments until reaching a failure load, but do not exceed the maximum testing load (200% of the foundation load). During each load interval, maintain load increments for 5 min and record test readings taken at 0.5, 1, 2 and 4 min after completing the application of each load increment. Use the same time interval for all loading increments through the test. Creep tests shall be performed at the test interval equal to 130 percent of the design load. Remove the load in six approximately equal increments. Keep the load constant for 5 min using the same time intervals for all unloading decrements. Record test readings taken at 1 and 4 min after completing each load decrements. Take and record readings at 1, 4, 8 and 15 min after removing all loads. Refer to a constant elevation benchmark for readings of settlements and rebounds. Record them to 0.01 in. for each increment or decrement of load.