46 GROUND ANCHORS AND SOIL NAILS
46-1 General
46-1.01 General
46-1.01A Summary
Section 46 -1 includes general specifications for constructing ground anchors and soil nails .
46-1.01B Definitions
Reserved
46-1.01C Submittals
46-1.01C(1) General
Submit a certified calibration chart for each jack and its gauge as an informational submittal.
46-1.01C(2) Shop Drawings
46-1.01C(2)(a) General
Submit shop drawings and supporting calculations el ectronically to sc.office.associates@dot.ca.gov . Shop drawings include:
1.General project information plan
2.Fabrication plan
3.Construction plan Shop drawings and calculations must be sealed and signed by an engineer who is registered as a civil engin eer in the State. Allow 30 days for the Department 's review.
46-1.01C(2)(b) General Project Information Plan
General project information plan must include:
1.Name, address, email address, and phone number of the contractor or subcontractor performing the work .
2.Wall construction schedule with construction sequence .
3.Wall construction staging schedule and layout of ground anchors and soil nails with identification number s of ground anchors and soil nails based on the following labeling convention: 3.1. Identification number "r_ccc ", where "r" represents row numbers starting with "1" or "A" from top to bottom and "ccc" represents column numbers starting with "001" from down -station to up-station. 3.2. For structures that include both ground anchors and soil nails, use separate identification systems and add "GA" for ground anchors and "SN" for soil nails preceding the identification number s. 3.3. Identify sacrificial test ground anchors and soil nails based on the nearest down -station production ground anchor and soil nail . Label the test type with "Proof Test ", "Verification Test ", or "Performance Test " preceding the identification numbers.
4.Table of lengths, tendon size s, centralizers , and drilled -hole diameters.
5.For ground anchors, calculations for determining the bonded length and assumed bonded strength. Do not rely on any capacity from the grout -to-ground bond within the unbonded length.
6.Procedures for installing verification and proof test nails .
7.Bench width requirements for installation equipment .
8.Excavation lift height and maximum duration of exposure for each wall zone, including : 8.1. Methods to stabilize the exposed excavate d face if face is not maintaining its integrity. 8.2. Supporting calculations .
46-1.01C(2)(c) Fabrication Plan
Fabrication plan must include:
1.Details and specifications for: 1.1. Ground anchors and anchorage system SECTION 46 GROUND ANCHORS AND SOIL NAILS 1.2. Production and test soil nails
2.Corrosion protection details and repair procedure for: 2.1. Damaged sheathing 2.2. Couplers
3.Testing equipment, including: 3.1. Jacking frame and appurtenant bracing 3.2. Method and equipment for measuring movement during testing 3.3. Calculations that demonstrate the jacking frame and appurtenant bracing can support the test equipment at maximum test load on the (1) soils or (2) structural element with factor of safety for bearing capacity greater than 2.0
4.For ground anchors, d etails for the transition between the corrugated plastic sheat hing and the anchorage assembly. If shims are used during lock -off, include: 4.1. Shim thickn ess 4.2. Supporting calculations You may start fabrication early by requesting an authorization of the fa brication plan portion before the complete shop drawings submittal is authorized. If the early fabrication plan is authorized, you are fully responsible for any changes that may occur after starting fabrication.
46-1.01C(2)(d) Construction Plan
Construction plan must include:
1.Methods of excavation for the staged lifts and types of excavation equipment .
2.Details for measuring the movement of the excavated face and the wall during stability testing and construction .
3.Measures to ensure wall and slope stability during construction.
4.Details for providing the bonded and unbonded length. If packers or other similar devices a re used, include the type.
5.For soil nails, d etails for isolating installed proof test soil nails during shotcrete appl ication .
6.Dewatering plan to divert, control, and dispose of surface and groundwater during construction
7.Drilling methods and equipment, including: 7.1. Size of drilled hole 7.2. Space requirements
8.Grout mix design and testing procedures .
9.Grout placement equipment and procedures, including minimum required cure time .
10.Testing equipment including m ethod and equipment for me asuring movement during testing.
11.For soil nails, include p rocedure for extracting grouted soil nails .
46-1.01C(3) Tes t Data
Submit each ground anchor and soil nail test data in both (1) electronic Quail XML format via email within 2 business days after the testing is complete and (2) hard copy format by noon the following working day after testing is complete. For each t est include:
1.Names of s upervisory personnel, subcontractors, and personnel performing the test
2.Test loading equipment
3.Ground anchor and soil nail i dentification number, location, and test type
4.Time and date of: 4.1. Drilling 4.2. Installation 4.3. Grouting 4.4. Testing
5.Hole diameter and depth
6.Drilling method
7.Soil or rock classification and description
8.Bonded and unbonded length
9.Quantity of groundwater encountered within the bonded length
10.Grout quantity and pressure used within the bonded length SECTION 46 GROUND ANCHORS AND SOIL NAILS
11.Anchor end or nail head movement at each load increment or at each time increment during the load hold period
12.Digital photo logs of extracted test ground anchors and soil nails Use the Quail Software to compile and submit completed data and test results for ground anchor and soil nail data. The Quail Software can be obtained on the Quail Software website. To access, install, download, and use the Quail Software, you must comply with the Departm ent’s “End User Click -Wrap Limited Software License to Use Agreement ” (“Agreement”) and agree to be bound by the terms and conditions in an online electronic format. This agreement is available on the Quail Software website. Compile and save test data usin g the Quai l Software. For a project with multiple structures, create and use one Quail XML file for each structure to compile test data. For each Quail XML file naming convention , use Project ID_BN.xml where Project ID is the project identification number and BN is the Department's structure number, as shown on the plans. For electronic submittal of the test data, e mail the file that includes the latest completed and compiled test data to Geotechnical.Data@dot.ca.gov and the Engineer. Use the following nami ng convention in the email subject line CQATD_Project ID_BN where CQATD is the abbreviation for Construction Quality Assurance Test Data . For the final Quail file submittal of each structure , use the following naming convention in the email subject line Final_CQATD _Project ID_BN .
46-1.01D Quality Assurance
46-1.01D(1) General
Welding must comply with AWS D1.1.
46-1.01D(2) Quality Control
46-1.01D(2)(a) General
Stability testing and wall zones must comply with section 19 -3.
46-1.01D(2)(b) Load Testing
46-1.01D(2)(b)(i) General
The jacking equipment and the movement measuring system must be stable during all phases of loading. Do not unload or reposition the test equipment during load testing.
46-1.01D(2)(b)(ii) Jacking Equipment and Calibration
Apply the test loads using a hydraulic jack supported by a reaction frame that can support the test equipment without excessive deformation. Use a calibrated pressure gauge or a load cell to determine the magnitude of applied test loads. The pressure gauge must have an accurately reading, clearly visible dial or display. Dial gauges must be graduated in 100 psi increments or less. Each jack and its gauge must be calibrated as a unit under the specifications for jacks used to tension prestressing steel permanently anchored at 25 percent or more of its specified minimum ultimate tensile strength in section 50 -1.01D(2)(b). The load cell must be calibrated and have an indicator capable of measuring the maximum test load. The load cell range must be such that the lower 10 percent of the manufacturer's rated capacity is not used in determining the jacking force.
46-1.01D(2)(b)(iii) Measuring Movements
The equipment for measuring the movement at the anchor end or nail head must be accurate to 0.001 inch and have enough capacity to complete the test without being reset . SECTION 46 GROUND ANCHORS AND SOIL NAILS
46-1.01D(2)(b)(iv) Procedure
At each load increment, including the ending alignment load, measure the movement at the anchor end or nail head relative to an independent, fixed reference point. Record the movements to the nearest 0.001 inch. Maintain eac h test load within 5 percent of the specified load throughout each hold period.
46-1.01D(3) Department Acceptance
The Department may verify the test loads using the Department's load cells. If requested, install and support the Department's testing equipm ent during testing and remove the equipment after testing is complete.
46-1.02 Materials
46-1.02A General
Reserved
46-1.02B Sheathing
PVC sheathing must comply with ASTM D1784, Class 13464 -B. HDPE sheathing must have a density of from 940 to 960 kg/m3 when measured under ASTM D792. Smooth and corrugated sheathing, including joints, must be:
1.Strong enough to prevent damage during construction
2.Watertight
3.Chemically stable without embrittlement or softening
4.Nonreactive with: 4.1. Concrete 4.2. Steel 4.3. Corrosion -inhibiting grease, if used The corrugation width, the distance between corrugations, and the corrugation height of corrugated plastic sheathing must be approximately equal.
46-1.02C Grout
Grout must consist of cement an d water and may contain an admixture if authorized. Cement must comply with section 90 -1.02B(2). Water must comply with section 90 -1.02D. Do not exceed 5 gallons of water per 94 lb of cement. Admixtures must comply with section 90, except they must not con tain chloride ions in excess of 0.25 percent by weight.
46-1.03 Construction
46-1.03A General
Water or grout from ground anchor and soil nail construction must not:
1.Fall on traffic
2.Flow across shoulders or lanes occupied by traffic
3.Flow into lan dscaping, gutters, or other drainage facilities Do not use an excessive quantity of water when drilling and installing ground anchors. Shotcrete must comply with section 53 -2.
46-1.03B Drilling
Drilled holes must not extend beyond the right -of-way or eas ement limits. Drilling equipment must produce straight, clean holes. SECTION 46 GROUND ANCHORS AND SOIL NAILS At locations where caving is anticipated, keep enough casing and auger lengths on the job site to maintain uninterrupted anchor or nail installation. At locations where hard drilling cond itions, such as rock, cobbles, boulders, or obstructions, are anticipated, keep a down -hole pneumatic hammer drill rig and drill bit available on the job site for drilling holes. Clean the holes to remove material from drilling activities. Do not use water to clean soil nail holes unless authorized. Dispose of drill cuttings under section 19 -2.03B.
46-1.03C Installation
Before you insert each ground anchor and soil nail into a drilled hole, clean the anchor or nail of oil, grease, dirt, and other extraneous substances and repair or replace any damaged sheathing. Use centralizers to position the ground anchor and soil nail in the center of the drilled hole. The diameter of the centralizers must be no more than (1) 0.5-inch smaller than the diameter of the drilled hole , or (2) 0.25-inch smaller than the inside diameter of casing, if casing is used. There must be no evidence of distress in the plastic sheathing or crushing of the grout within the pregrouted sheathing. Do not insert an anchor or nail into a hole until the hole has been inspected by the Engineer. Install the anchor or nail in the drilled hole promptly so that caving or deterioration of the hole does n ot occur. If you cannot insert an anchor or nail into a drilled hole to the required depth without difficulty, remove the anchor or nail and clean or redrill the hole. Do not force or drive a partially inserted anchor or nail into a drilled hole. Partially inserted anchors or nails are rejected. For open -hole drilling methods, keep hole -cleaning tools on the job site. The tools must be suitable for cleaning drilled holes along their full length just before inserting the anchor or nail.
46-1.03D Grouting
Mix the grout as follows:
1.Add water to the mixer followed by cement and any admixtures or fine aggregate.
2.Mix the grout with mechanical mixing equipment that produces a uniform and thoroughly mixed grout.
3.Agitate the grout continuously until the gro ut is pumped.
4.Do not add water after the initial mixing. Grouting equipment must be:
1.Capable of grouting at a pressure of at least 100 psi
2.Equipped with a pressure gauge having a full -scale reading of not more than 300 psi
46-1.03E Research Inv estigation
Reserved
46-1.04 Payment
Not Used
46-2 Ground Anchors
46-2.01 General
46-2.01A Summary
A ground anchor consists of a steel bar or strand tendon with an anchorage assembly that is placed in a cored, formed, or drilled hole, and then grouted and stressed. SECTION 46 GROUND ANCHORS AND SOIL NAILS
46-2.01B Definitions
lock-off load: Load maintained on the jacks while the anchor head or anchor nuts on the ground anchor are permanently set.
46-2.01C Submittals
Submittals for strand tendons, bar tendons, bar couplers, and anchorage assemblies must comply with section 50 -1.01C. At least 40 days before using the corrosion -inhibiting grease, submit a test sample from the lot to be used and test data showing compliance with the specifications for strand coating and encapsulation. If a pullout failure occurs, submit the pullout failure load as part of the test data.
46-2.01D Quality Assurance
46-2.01D(1) General
Reserved
46-2.01D(2) Quality Control
46-2.01D(2)(a) General
Strand tendons, bar tendons, bar couplers, and anchorage assemblies must comply with section 50 - 1.01D.
46-2.01D(2)(b) Load Testing
46-2.01D(2)(b)(i) General
Performance test ground anchors as described . Proof test all ground anchors that are not performance tested. Perform load testing against the completed structural element shown. Do not test directly against the soil. Do not stress against the concrete until it has attained a compressive strength of at least 2,880 psi and has cured for at least 7 days. Bearing pads must be a minimum of 1 foot away from the edges of the drilled hole. If a ground anchor fails to comply with the acceptance criteria, redesign or replace the ground anchor. Do not retest a ground anchor unless you post -grout the anchor bonded length after the unacceptable test.
46-2.01D(2)(b)(ii) Test Procedure
Conduct the performance and proof tests as follows:
1.Incrementally load and unload the anchor as shown in the following table: SECTION 46 GROUND ANCHORS AND SOIL NAILS Loading Schedules Performance test Proof test Load increment Hold time (minutes) Load increment Hold time (minutes) AL Until stable AL Until stable 0.20PTL 1–2 0.20PTL 1–2 AL Until stable 0.40PTL 1–2 0.20PTL 1–2 0.60PTL 1–2 0.40PTL 1–2 0.80PTL 1–2 AL Until stable a1.00PTL 10 or 60 0.20PTL 1–2 AL Until stable 0.40PTL 1–2 -- -- 0.60PTL 1–2 -- -- AL Until stable -- -- 0.20PTL 1–2 -- -- 0.40PTL 1–2 -- -- 0.60PTL 1–2 -- -- 0.80PTL 1–2 -- -- AL Until stable -- -- 0.20PTL 1–2 -- -- 0.40PTL 1–2 -- -- 0.60PTL 1–2 -- -- 0.80PTL 1–2 -- -- a1.00PTL 10 or 60 -- -- AL Until stable -- -- NOTES: PTL = Test load shown AL = Alignment load = 0.10 PTL aMaximum test load
2.Apply each load increment in less than 1 minute and hold it for the length of time shown in the table titled "Loading Schedules."
3.Measure and record the applied test load and the anchor end movement at each load increment.
4.When applying the maximum test load: 4.1. Hold the load constant for 10 minutes 4.2. Start the observation period for the load hold when the pump starts to apply the last load increment 4.3. Measure and record the anchor end movement at 1, 2, 3, 4, 5, 6, and 10 minutes
5.If the movement measured from 1 to 10 minutes is greater than 0.04 inch: 5.1. Hold the load constant for an additional 50 minutes 5.2. Measure and record the anchor end movement at 15, 20, 25, 30, 45, and 60 minutes 5.3. Plot a creep curve as a function of the logarithm of time, showing the anchor end movement from 6 to 60 minutes
6.Reduce the load to the ending alignment load and record the residual movement.
46-2.01D(3) Department Acceptance
46-2.01D(3)(a) General
The Department tests the efflux time of the grout under California Test 541.
46-2.01D(3)(b) Load Testing
46-2.01D(3)(b)(i) General
Incrementally load the ground anchor until the maximum test load is held for the specified duration or a pullout failure occurs. If a pullout failure occurs, record the pullout failure load.
46-2.01D(3)(b)(ii) Acceptance Criteri a
Ground anchors that are performance -or proof -tested must comply with the following: SECTION 46 GROUND ANCHORS AND SOIL NAILS
1.Total measured movement at the maximum test load minus the measured residual movement at the ending alignment load exceeds 80 percent of the theoretical elastic elong ation of the sum of the unbonded length and the jacking length.
2.Creep movement complies with one of the following: 2.1. For a 10 -minute load hold, the creep movement measured from 1 to 10 minutes is less than 0.04 inch. 2.2. For a 60 -minute load hold, t he creep movement measured from 6 to 60 minutes is less than 0.08 inch and the creep rate is linear or decreasing in time logarithmic scale from the 6 -to the 60-minute reading.
3.Pullout failure does not occur.
46-2.02 Materials
46-2.02A General
If a bond breaker is shown near the bearing plate, use a 1/4 -inch premolded joint filler that complies with section 51 -2.01B(1).
46-2.02B Steel
Strand tendons, bar tendons, and bar couplers must comply with section 50 -1.02B and must be on the Authorized Materi al List for post -tensioning systems. The anchorage enclosure and the steel tube and bearing plate of the anchorage assembly must be galvanized steel and comply with sections 55 -1.02D(1) and 55 -1.02E(1). Section 11 -2 does not apply to the anchorage enclosur e welds or to the weld between the steel tube and the bearing plate. The permanent bearing plate must effectively distribute the test load uniformly to the concrete such that:
1.Concrete bearing stress does not exceed 2,400 psi
2.Bending stress of the pl ate does not exceed: 2.1. 0.90 of the yield strength for steel 2.2. 0.55 of the yield strength for cast steel or cast iron
46-2.02C Sheathing
46-2.02C(1) General
Polypropylene sheathing must have a density of from 900 to 910 kg/m3 when measured under ASTM D792.
46-2.02C(2) Smooth Plastic Sheathing
Smooth sheathing for bar tendons must be PVC or HDPE. Smooth sheathing for encapsulating individual strands of strand tendons must be HDPE or polypropylene and must have a minimum wall t hickness of 40 mils.
46-2.02C(3) Corrugated Plastic Sheathing
Corrugated plastic sheathing must be PVC or HDPE. PVC corrugated sheathing must have a nominal wall thickness of 40 mils. HDPE corrugated sheathing with an outside diameter of 3 inches or great er must have a nominal wall thickness of 60 mils. HDPE corrugated sheathing with an outside diameter of less than 3 inches must have a nominal wall thickness of 40 mils.
46-2.02D Strand Coating and Encapsulation
Within the unbonded length of strand tendon s, fully coat each individual strand with corrosion -inhibiting grease and encapsulate it with a smooth HDPE or polypropylene sheath. Hot melt extrude or shop apply the sheath onto the strand using a method that ensures all spaces between the sheath, strand , and strand wires are filled with corrosion -inhibiting grease. The corrosion -inhibiting grease must:
1.Fill all space between the strand wires SECTION 46 GROUND ANCHORS AND SOIL NAILS
2.Encapsulate the strand, giving an encasement diameter at least 5 mils greater than the diameter of the bare strand
3.Provide a continuous, nonbrittle film of corrosion protection to the prestressing steel
4.Provide lubrication between the strand and the sheathing
5.Resist flow from the sheathing
6.Be chemically stable and nonreactive with the prestressing st eel, sheathing material, and concrete
7.Be organic
8.Have appropriate polar, moisture -displacing, and corrosion -inhibiting additives
9.Have the physical properties shown in Table 4.1 of Recommendations for Prestressed Rock and Soil Anchors published by the Post -Tensioning Institute
46-2.02E Grout
The efflux time of the grout immediately after mixing must be at least 11 seconds. For drilled holes 8 inches or larger in diameter, you may add fine aggregate to the grout used outside of the corrugated sheat hing. The fine aggregate must comply with section 90 -1.02C. Grout with fine aggregate must contain at least 845 pounds of cement per cubic yard.
46-2.03 Construction
46-2.03A General
Ground anchor installation must comply with the manufacturer's instructions unless otherwise specified. Determine the bonded length necessary to comply with the specified acceptance criteria. Sheathe the tendons in the unbonded length with smooth plastic sheathing that extends into the steel tube of the permanent anchorage assembly. Sheathe the tendons full length with corrugated plastic sheathing. The transition between the corrugated plastic sheathing and the anchorage assembly must allow stressing to the maximum test load without evidence of distress in the corrugated plastic sheathing. Select a ground anchor installation method that achieves the loadings specified. Do not drill for ground anchors in a wall zone until any required stability testing is complete and the test results are authorized. Drill the holes for ground anchors in the foundation material deep enough to provide the necessary bonded length beyond the minimum unbonded length shown. If coring through concrete structures, core the holes using methods that do not shatter or damage the conc rete adjacent to the hole. The diameter of the drilled hole must be large enough to provide a minimum grout cover of 1 inch over the corrugated sheathing for the full length of the tendon. Before installing a ground anchor, repair or replace any damaged po rtions of the sheathing. Space centralizers at 5 -foot maximum intervals for the full length of the tendon, with the uppermost centralizer located less than 2 feet from the end of the steel tube and the deepest centralizer located 2 feet from the end of the anchor. Pregrout each tendon at least 48 hours before you place the tendon in the drilled hole. At each grouting stage, inject the grout at the low end of the void to be filled. Place the grout using grout tubes. Do not place grout in the unbonded leng th under pressure. Record the quantity of grout and the grout pressures. If hot weather conditions will contribute to quick stiffening of the grout, cool the grout by authorized methods as necessary to prevent blockages during pumping activities. After ini tial grouting, the anchor must remain undisturbed until the grout is strong enough to provide anchorage during load testing. SECTION 46 GROUND ANCHORS AND SOIL NAILS Protect the anchorage assembly against rust, corrosion, and physical damage until the enclosure is grouted or the assembly is encas ed in concrete. For ground anchors installed inside driven structural elements such as pipe, casing, shells, and pipe piles, construct the drilled hole in the foundation material as follows:
1.Use construction methods that do not reduce the compression or tension capacity of the driven element.
2.After the driven element is installed, advance the anchor hole with a drill casing using rotary methods to at least 10 feet beyond the tip of the driven element. Do not use percussion drilling until the casing is in place.
3.Do not extract the casing until the tendon is installed, and the portion of the initial grout outside the corrugated sheathing and within the bonded length has been placed.
46-2.03B Bar Tendons
For bar tendons, provide a seal between the sm ooth sheathing and the corrugated sheathing at the top and bottom of the length of smooth sheathing. Center the bar in the corrugated sheathing and pregrout the annular space between the bar and the sheathing before placing the tendon in the drilled hole. You may place the initial grout in the drilled hole before or after inserting the bar tendon. Stress the bars for multiple -bar tendons simultaneously.
46-2.03C Strand Tendons
Use spacers to separate individual strands of strand tendons within both the bonded and unbonded lengths so that the entire surface of each strand is bonded in the grout in the bonded length and each sheathed strand is surrounded by grout in the unbonded length. The spacers must be:
1.Spaced at 5 feet maximum
2.Less than 2 feet f rom the ends of the strand tendon
3.Made of plastic
4.Strong enough to support the individual strands during construction Pregrout the corrugated sheathing a minimum length of 2 feet before inserting the strand tendon in the hole. After inserting the st rand tendon and before placing the initial grout in the hole, inject grout into the corrugated sheathing to the limits shown.
46-2.03D Lock -off
After a successful ground anchor test, tension the anchor and lock it off at the lock -off load shown. Secure th e ends of strand tendons with a permanent -type anchorage system that:
1.Holds the prestressing steel at a force producing a stress of at least 95 percent of the specified ultimate tensile strength of the steel
2.Permanently secures the ends of the prestr essing steel Lock off strand tendons as follows:
1.Stress the tendon to the maximum test load.
2.Fully set the permanent wedges in the anchor head.
3.Remove the shims or use other appropriate means to achieve the lock -off load shown. Immediately after lock-off, perform a lift -off test to verify that the lock -off load has been attained. The lift - off load must be within 10 percent of the specified lock -off load. If necessary , adjust the shim thickness to achieve the lock -off load. If the load is not with in 10 percent of the specified lock -off load, the anchorage must be reset and another lift -off load reading must be made. Repeat the process until the specified lock - off load is obtained. SECTION 46 GROUND ANCHORS AND SOIL NAILS After lock -off, place grout to the secondary grout level shown. At l east 24 hours after the secondary grout has set, fill the remaining void in the steel tube and bearing plate with grout. Maintain a minimum grout head of 2 feet until the grout has set. If a grouted anchorage enclosure is shown, install the enclosure as fo llows:
1.Grout the steel tube.
2.Clean the bearing plate surface.
3.Place the sealant.
4.Bolt the anchorage enclosure in place.
5.Fill the void in the anchorage enclosure with grout.
6.Clean and seal any holes in the top of the anchorage enclosure used for grout placement. Use a nonsag polysulfide or polyurethane sealing compound that complies with ASTM C920.
46-2.04 Payment
Not Used
46-3 Soil Nails
46-3.01 General
46-3.01A Summary
A soil nail consists of a solid steel bar with an anchorage assembly that is placed in a drilled hole and then grouted.
46-3.01B Definitions
pullout failure: Occurrence in which attempts to increase the test load result in nail head movement relative to a fixed reference point without an increase in load.
46-3.01C Submittals
46-3.01C(1) General
If a pullout failure occurs, submit the pullout failure load as part of the test data. If production soil nails are rej ected under section 46 -3.01D(2)(b)(ii)(C), submit revised shop drawings. If additional verification soil nails are required under section 46 -3.01D(2)(b)(ii)(B), submit revised shop drawings.
46-3.01C(2) Test Boring Report
If additional verification soil n ails are required under section 46 -3.01D(2)(b)(ii)(B), submit a test boring report for the additional verification soil nails. The test boring report must include:
1.Summary of drilling methods, drilling equipment, drill platforms, and drilling difficulti es encountered
2.Location map of the surveyed position of the new test borings relative to existing and proposed facilities in the California Coordinate System and bridge stationing
3.Bore hole surveying notes
4.Depth increments of borings
5.Soil and r ock classifications and descriptions
6.Photographs of cuttings
7.Copies of original daily drilling notes, including dates and weather conditions Classify soil and rock under the Soil and Rock Logging, Classification, and Presentation Manual . For the manual, go to the Geotechnical Services Web site. The test boring report must be sealed and signed by a geologist or engineer registered as a geologist or civil engineer in the State. SECTION 46 GROUND ANCHORS AND SOIL NAILS
46-3.01D Quality Assurance
46-3.01D(1) General
Reserved
46-3.01D(2) Q uality Control
46-3.01D(2)(a) General
Reserved
46-3.01D(2)(b) Load Testing
46-3.01D(2)(b)(i) General
Perform load testing of verification and proof test soil nails to verify the installation methods and pullout resistance . Load testing must include incrementally loading the soil nail until the maximum test load is held for the specified duration or a pullout failure occurs. If a pullout failure occurs, record the pullout failure load.
46-3.01D(2)(b)(ii) Test Procedure
46-3.01D(2)(b)(ii)( A) General
Determine the test load using the following equation: T = Lb x Qb where: T = test load, pounds Lb = soil nail bonded length , feet, 10 feet minimum for proof test; 8 feet minimum for verification test Qb = test load per unit len gth of bond, pounds/foot
46-3.01D(2)(b)(ii)( B) Verification Test
Perform verification testing in the Engineer's presence. Install and test 2 verification test soil nails (1) for each wall zone, or (2) when you change equipment or method of drilling or grouting. You may install and test the nails during stability testing. Conduct the verification test as follows:
1.Incrementally load the test soil nail as shown in the following t able: Verification Test Loading Schedule Load increment Hold time (minutes) AL Until stable 0.20T 1–2 0.40T 1–2 0.60T 1–2 0.80Ta 60 1.00Tb,c 10 AL Until stable NOTES: T = Test load AL = Alignment load = 0.10T aCreep test. bAcceptance test load for verification test. cMaximum test load for verification test.
2.Apply each load increment in less than 1 minute and hold it for the length of time shown in the table titled "Verification Test Loading Schedule."
3.Measure and record the applied test load and the nail head movement at each load increment.
4.During the creep test: 4.1. Hold the load constant for 60 minutes SECTION 46 GROUND ANCHORS AND SOIL NAILS 4.2. Start the observation period for the load hold when the pump starts to apply the load increment from 0.60T to 0.8 0T 4.3. Measure and record the nail head movement at 1, 2, 3, 4, 5, 6, 10, 15, 20, 25, 30, 45, and 60 minutes 4.4. Plot a creep curve as a function of the logarithm of time, showing the nail head movement from 6 to 60 minutes
5.If the movement measured fr om 6 to 60 minutes is less than 0.08 inch: 5.1. Increase the load incrementally to 1.00T 5.2. Hold the load constant for 10 minutes 5.3. Start the observation period for the load hold when the pump starts to apply the load increment from 0.80T to 1.00T 5.4. Measure and record the nail head movement at 1, 2, 3, 4, 5, 6, and 10 minutes 5.5. Reduce the load to the ending alignment load and record the residual movement
6.If the movement measured from 6 to 60 minutes is 0.08 inch or greater, reduce the load to the ending alignment load. Verification test soil nails that fail to comply with the acceptance criteria are rejected. Submit revised shop drawings for additional verification test soil nails. The Engineer determines the cause of failure for each rejected verification test soil nail. If the Engineer determines that the installation methods are the cause of failure, the installation methods are rejected. Show alternative installation methods on the revised shop drawings. If the Engineer revises soil nail le ngths or test load per unit length of bond values, any additional verification test soil nails are change order work. Install and test additional verification test soil nails until they comply with the acceptance criteria. Log horizontal borings for additi onal verification test soil nails and submit a test boring report under section 46 -3.01C. The logging of horizontal test borings and the submittal of the test boring report is change order work.
46-3.01D(2)(b)(ii)( C) Proof Test
Perform proof testing in th e Engineer's presence at the locations shown. Production soil nails will be authorized when all the proof test soil nails within the same wall zone are authorized . Test against a temporary yoke that bears directly on the shotcrete facing. Test loads transmitted through the temporary yoke must not fracture the shotcrete or cause displacement or sloughing of the soil surrounding the drilled hole. Conduct the proof test as follows:
1.Incrementally load the test soil nail as shown in the following table: SECTION 46 GROUND ANCHORS AND SOIL NAILS Proof Test Loading Schedule Load increment Hold time (minutes) AL Until stable 0.20T 1–2 0.40T 1–2 0.60T 1–2 0.80Ta 10 or 60 1.00Tb,c 1–2 AL Until stable NOTES: T = Test load AL = Alignment load = 0.10T aCree p test. bAcceptanc e test load for proof test . cMaximum test load for proof test .
2.Apply each load increment in less than 1 minute and hold it for the length of time shown in the table titled "Proof Test Loading Schedule."
3.Measure and record the applied test load and the nail head mo vement at each load increment.
4.During the creep test: 4.1. Hold the load constant for 10 minutes 4.2. Start the observation period for the load hold when the pump starts to apply the load increment from 0.80T to 1.00T 4.3. Measure and record the nail he ad movement at 1, 2, 3, 4, 5, 6, and 10 minutes
5.If the movement measured from 1 to 10 minutes is greater than 0.08 inch: 5.1. Hold the load constant for an additional 50 minutes 5.2. Measure and record the nail head movement at 15, 20 , 25, 30, 45, and 6 0 minutes 5.3. Plot a creep curve as a function of the logarithm of time, showing the nail head movement from 6 to 60 minutes
6.Reduce the load to the ending alignment load and record the residual movement. Production soil nails represented by proof test soil nails that fail to comply with the acceptance criteria are rejected. Submit revised shop drawings for replacement soil nails that show alternative installation methods, revised production soil nails, or a modified soil nail plan.
46-3.01D(2)(c) Grout
Before using grout with fine aggregate, produce a test batch to verify the consistency. Produce and deliver the test batch under conditions and in time periods similar to those expected during the grouting of soil nails. Place the test batch grout in an excavated hole or a container of suitable size to allow testing under California Test 533. The test batch must comply with the specified nominal penetration. Dispose of the grout after testing.
46-3.01D(3) Department Acceptance
46-3.01D(3)(a) General
The Department tests grout with fine aggregate under California Test 533 before use.
46-3.01D(3)(b) Load Testing
46-3.01D(3)(b)(i) General
Reserved
46-3.01D(3)(b)(ii) Acceptance Criteria
Soil nails that are verification -or proof -tested must comply wit h the following:
1.For verification tests: SECTION 46 GROUND ANCHORS AND SOIL NAILS 1.1. Creep movement measured from 6 to 60 minutes is less than 0.08 inch. 1.2. Creep rate is linear or decreasing in time logarithmic scale from the 6 -to the 60 -minute reading.
2.For proof tests, the creep move ment complies with one of the following: 2.1. Creep movement measured from 1 to 10 minutes is no more than 0.08 inch. 2.2. Creep movement measured from 6 to 60 minutes is less than 0.08 inch and the creep rate is linear or decreasing in time logarithmic sc ale from the 6 -to the 60 -minute reading.
3.Total measured movement at the maximum test load minus the measured residual movement at the ending alignment load exceeds 80 percent of the theoretical elastic elongation of the unbonded length.
4.Pullout fail ure does not occur.
46-3.02 Materials
46-3.02A General
Each production soil nail must be either a solid steel bar encapsulated full length in a grouted corrugated plastic sheathing or an epoxy -coated prefabricated solid steel bar partially encapsulated in a grouted corrugated plastic sheathing as shown. Epoxy -coated prefabricated solid steel bars must comply with the specifications for epoxy -coated prefabricated reinforcement in section 52 -2.03, except the average coating thickness after cur ing must be from 10 to 15 mils. Solid steel bar for test soil nails is not required to be epoxy coated or encapsulated in grouted plastic sheathing.
46-3.02B Anchorage Assemblies
Soil nail anchorage assemblies must comply with section 75 -2, except galvani zing is not required for nuts, washers, wedges, and bearing plates if they are fully encased in concrete, grout, or shotcrete. Concrete anchors on bearing plates must comply with the specifications for studs in clause 9 of AWS D1.1.
46-3.02C Solid Steel B ars
Solid steel bars must be either:
1.Threaded bars with spirally -deformed, ribbed threads continuous along the entire length of the bar.
2.Deformed reinforcing bars with at least a 6 -inch length of thread cut into the bar on the anchorage end. Use coar se threading and the next larger reinforcing bar size. Solid steel bars must comply with ASTM A615/A615M or A706/A706M, Grade 60 or ASTM A615/A615M, Grade 75. Splicing must be authorized. Epoxy coating at the anchorage end of epoxy -coated bars may be omit ted for a maximum of 6 inches. Metal surfaces of assembled splices of epoxy -coated bars must be epoxy coated. Choose the solid steel bar size and grade for test soil nails. Test soil nail bars must not be smaller than the production soil nails they represe nt.
46-3.02D Sheathing
Corrugated plastic sheathing must be PVC or HDPE and must have a minimum thickness of 25 mils.
46-3.02E Grout
For drilled holes 6 inches or larger in diameter, you may add fine aggregate to the grout. Grout with fine aggregate must :
1.Contain at least 845 pounds of cement per cubic yard of grout
2.Use fine aggregate that complies with section 90 -1.02C
3.Have a nominal penetration of at least 3 -1/2 inches when measured under California Test 533
4.Have an air content of no more th an 2 percent when measured under California Test 504 SECTION 46 GROUND ANCHORS AND SOIL NAILS
5.Not contain air -entraining admixtures
46-3.03 Construction
46-3.03A General
Determine the drilled -hole diameter and installation method required to achieve the test load per unit length of bond values shown. Do not drill for proof test or production soil nails in a wall zone until stability testing, if required, and verification soil nail testing are complete in the wall zone and the test results are authorized. If you are ordered to lengthen ver ification or proof test soil nails, the lengthening of test soil nails is change order work. If you are ordered to lengthen production soil nails or install additional production soil nails, the lengthening or addition of production soil nails is change or der work.
46-3.03B Test Soil Nails
Construct verification and proof test soil nails using the same equipment, methods, nail inclination, and drilled hole diameter as to be used for production soil nails. Drill, install, and grout verification test soil na ils in the Engineer's presence. Install the verification test soil nails within the limits of each wall zone or within the limits of the excavated stability test face. Space the verification test soil nails at least 10 feet apart. Grout only the bonded len gth of verification and proof test soil nails. Form the terminating grout surface perpendicular to the soil nail alignment using a forming device. The forming device must:
1.Have a diameter no more than 1 inch smaller than the drilled hole diameter
2.Be made of materials that can form a minimum 8 -inch compressible zone measured along the test soil nail alignment
3.Not deform during test soil nail installation Grout overflow above the forming device is allowed , but the forming device must not be submerge d by overflowed grout. Do not splice a test soil nail within the bonded length. Remove each verification and proof test soil nail to 6 inches behind the front face of the shotcrete after testing is complete. Fill the voids with grout. If ordered, extract v erification and proof test soil nails selected by the Engineer. Fill the voids with grout. Photograph the extracted test nails in 5 -foot section intervals.
46-3.03C Installation
Install and grout the soil nails in the same work shift that the holes are dr illed. Space the centralizers at 7.5 feet maximum intervals along the bar length and 1.5 feet from the bar ends. You may use plastic centralizers. Splice the solid steel bar only where shown on the authorized shop drawings or at the end of a soil nail that is ordered to be lengthened. Verify and record the drilled hole length before grouting. Grout the drilled hole after installing the soil nail. Inject the grout at the low end of the drilled hole. Fill the drilled hole with a dense grout, free of voids and foreign material. Grout the hole in 1 continuous operation. Do not use cold joints in the grout placement. Fill any void remaining at the open end of the drilled hole of a production soil nail with shotcrete. Secure the soil nail at the face of the shotcrete. The bearing plate must have full bearing on the shotcrete surface. SECTION 46 GROUND ANCHORS AND SOIL NAILS Hand tighten the nut on the end of the production soil nail bar before shotcrete hardening begins. Ensure the bearing plate is fully seated on the shotcrete . Make the nut wrench tight after the shotcrete has set for 24 hours, unless a shorter time is authorized. After placing the grout, the soil nails must remain undisturbed for the minimum cure time shown on the authorized shop drawings.
46-3.04 Payment
The payment quantity for soil nails is the length measured along the bar centerline from the back face of shotcrete to the tip end shown or ordered. Verification and proof test soil nails are paid for as soil nails.
46-4 46-10 Reserved
Source: California Standard Specifications, 2024 Edition. Pages 669–686 of 1,372.