02831Mse Retaining Walls

MSE RETAINING WALLS – GENERAL REQUIREMENTS

PART 1 GENERAL

1.1SECTION INCLUDES

walls of the following types:

reinforcement.

reinforcement.

reinforcement.

1.2RELATED SECTIONS

1.3REFERENCES

Products

Earth Walls and Reinforced Slopes – Volumes I and II”, November 2009 (GEC 11)

1.4DEFINITIONS Not Used

MSE Retaining Walls – General Requirements

1.5SUBMITTALS

preconstruction meeting.

representative assigned to the project.

each person that provides direct supervision over each MSE wall construction crew.

will be built per the authorized plans, tolerances and other specification requirements specific to the wall system being used will be met.

compaction requirements are being met.

be maintained during construction to assure consistency in meeting specification requirements. 1) Include appropriate control points where measurements are taken to verify compliance with facing tolerances. 2) Include checklists that document compliance with the quality control plan, the Wall Company’s construction manual and specification requirements.

available on the Department’s website as a baseline. Refer to http://www.udot.utah.gov/go/standardsreferenc es

system

MSE Wall Company’s technical representative.

MSE Retaining Walls – General Requirements

color requirements shown.

1) Plans, profiles, cross-sections, quantities, and details for each retaining wall. 2) Cast-in-place concrete coping or cap to the facing panels or blocks.

shown.

Engineer’s prior approval. 3) Measures for protecting metal soil reinforcement and metal reinforcement connections from corrosion. 4) Provisions for facilities that penetrate the wall face or soil reinforcement, such as drainage catch basins, piping, foundation elements, guard-rail posts, and other buried facilities. 5) Surface and subsurface drainage details. 6) Architectural treatment details for wall facing elements and concrete color as shown. 7) Structure number details

the retaining walls are designed according to the required criteria.

Professional Structural Engineer (SE) licensed in the State of Utah on the drawings and calculations.

tests performed for information. Include at least the following in addition to the certificate of compliance general requirements:

freeze-thaw durability, absorption, density, and dimensional tolerances.

MSE Retaining Walls – General Requirements

cap mesh, woven wire mesh) and other steel elements (loop embeds, fasteners, tie strips, lifting devices, connector rods, hairpin connectors)

1) Ultimate tensile strength 2) Ultimate weld strength for mesh soil reinforcement 3) Galvanization coverage including amount applied and average thickness

instructions

for each geogrid product is greater than or equal to the geogrid ultimate wide width tensile strength published in the manufacturer’s product data sheet and installation instructions.

and the following reinforcement reduction factors: 1) Long term tension creep 2) Durability 3) Installation damage

panel bearing pads, facing infill rock, and modular block fill

the manufacturer that are necessary to verify compliance with the specified requirements.

requirements for the authorized retaining wall drawings.

following:

MSE Retaining Walls – General Requirements

reinforcement gradation is to be used in a wall that uses geogrid reinforcement for review.

damage reduction factor.

Quality Coordinator certifying that the wall construction complies with the specified requirements and the submitted quality control plan.

Wall Company requirements based upon the Wall Company’s technical representative’s onsite observations.

1.6QUALITY CONTROL

Company. The Wall Company’s technical representative must:

on at least five walls of similar size and type within the previous five years.

the Contractor’s wall construction crew(s) and Department inspectors regarding proper quality control for construction of the walls.

phases of wall construction.

1) The first five working days of the construction of each wall and until all aspects of wall construction have been satisfactorily demonstrated to the Wall Company’s technical representative and the Engineer.

working days of both the first and second stage of wall construction for two-stage wall systems.

MSE Retaining Walls – General Requirements

2) The Department reserves the right to require the Wall Company’s technical representative to be onsite at no additional cost to the Department if at any time the Engineer is concerned with the construction quality.

to report on the observed wall construction procedures.

quality coordinator must:

retaining walls of similar size and type within the previous five years.

representative and the Engineer to verify issues and potential issues are properly addressed in a timely manner.

procedures are implemented according to the MSE wall quality plan.

responsibilities

according to the MSE wall quality plan.

construction training.

when the MSE wall exposed area for the project is greater than 20,000 sq ft.

site. MSE wall onsite supervisor(s) must:

retaining walls of similar size and type within the previous five years, at least three of which were in a supervisory role.

construction.

wall construction begins. Include at least the following:

Company’s construction manual.

MSE Retaining Walls – General Requirements

MSE wall quality plan.

representative conduct the training.

attend the initial training.

upon request.

supervisor and MSE wall quality coordinator.

1.7ACCEPTANCE

wall to remain in place at a reduced price when the wall facing elements do not meet the specified tolerances, provided that the retaining wall is adequate to serve the design purpose.

serve the design purpose.

upon aesthetics, geometry, and structural integrity.

is complete. 1) Measurements may be taken before the wall coping is placed to facilitate measuring.

and types by visual inspection.

measurement type (vertical alignment, plumbness, facing element levelness, joint width, and joint offset) according to Table 1.

MSE Retaining Walls – General Requirements

total pay factor for the wall for each measurement type.

weighted average. 1) The weighted average is calculated by multiplying the segment pay factor by the segment wall area divided by the total wall area and combining the results for all wall segments.

Table 1 must be corrected or deemed adequate to serve the design purpose with a segment pay factor determined by the Engineer before final payment for the wall is made. 1) A pay factor of 0.5 will be used for wall segments that are allowed to remain in place when listed as “Reject”.

from the total pay factors for each measurement type.

sum price for the wall in the Bid Schedule by the governing pay factor.

the pay factor calculations.

MSE Retaining Walls – General Requirements

Table 1 Pay Factors For Out-Of-Tolerance MSE Wall Facing Elements* Measurement Pay Wall Facing Measurements Type Factor Over 1%** Over 10%** Over 20%** Over 30%** Applicable to Concrete Panel and Modular Block MSE Wall Types 1.00 --- --- --- --- Vertical 0.95 over 1.75 over 1.40 over 1.05 over 0.70 Alignment*** 0.90 over 2.10 over 1.75 over 1.40 over 1.05 (percent) 0.80 over 2.45 over 2.10 over 1.75 over 1.40 Spec: 0.7% 0.60 over 2.80 over 2.45 over 2.10 over 1.75 Reject over 3.15 over 2.80 over 2.45 over 2.10 Reject over 4.20 over 3.70 over 3.20 over 2.70 0.60 over 3.70 over 3.20 over 2.70 over 2.20 0.80 over 3.20 over 2.70 over 2.20 over 1.70 Plumbness

0.95 over 2.20 over 1.70 over 1.20 over 0.70 Spec: 1.00 --- --- --- --- Positive: 0.7% 0.95 over -1.30 over -1.00 over -0.70 over -0.40 Negative: 0.90 over -1.60 over -1.30 over -1.00 over -0.70 -0,4% 0.80 over -1.90 over -1.60 over -1.30 over -1.00 0.60 over -2.20 over -1.90 over -1.60 over -1.30 Reject over -2.50 over -2.20 over -1.90 over -1.60 1.0 --- --- --- --- 0.95 over 0.80 over 0.70 over 0.60 over 0.50 Levelness

0.8 over 1.00 over 0.90 over 0.80 over 0.70 Spec: 0.5% 0.6 over 1.10 over 1.00 over 0.90 over 0.80 Reject over 1.20 over 1.10 over 1.00 over 0.90

MSE Retaining Walls – General Requirements

Table 1 (continued) Pay Factors For Out-Of-Tolerance MSE Wall Facing Elements* Measurement Pay Wall Facing Measurements Type Factor Over 1%** Over 10%** Over 20%** Over 30%** Applicable to Concrete Panel MSE Retaining Walls Only Reject under 0.062 under 0.062 under 0.125 under 0.250

0.6N/A under 0.125 under 0.250 under 0.375

Joint Width 0.8 under 0.125 under 0.250 under 0.375 under 0.500

1.0 --- --- --- --- Spec: 0.5 to 1.25 0.9 over 1.625 over 1.500 over 1.375 over 1.250 0.8 over 1.750 over 1.625 over 1.500 over 1.375 0.6 over 1.875 over 1.750 over 1.625 over 1.500 Reject over 2.000 over 1.875 over 1.750 over 1.625 1.0 --- --- --- --- Joint Offset

0.9 over 0.875 over 0.750 over 0.625 over 0.500 Spec: 0.8 over 1.000 over 0.875 over 0.750 over 0.625 0.375 0.6 over 1.125 over 1.000 over 0.875 over 0.750 Reject over 1.250 over 1.125 over 1.000 over 0.875 * Tolerances are according to Sections 02833 and 02835. ** Wall percentage corresponding to out-of-tolerance measurements. Wall percentage is based on face area, wall lineal footage, or length of joints, as applicable for the measurement type. For plumbness of concrete panel walls, the Over 1% column represents one 10 ft wide section of panels that is out of tolerance, the Over 10% column represents two panel columns out of tolerance, etc. *** Vertical alignment is measured as the difference in percent slope at a bulge or depression. For concrete panel walls, measurement is between adjacent panels. For modular block walls, the slope measurement is between points of maximum and minimum horizontal offset.

PART 2 PRODUCTS

2.1MSE RETAINING WALL TYPES

type shown.

Department.

MSE Retaining Walls – General Requirements

the Wall Company’s authorized supplier.

Company’s published requirements.

shown.

shown.

without the Engineer’s approval.

2.2DESIGN REQUIREMENTS

LRFD Bridge Design Specifications, as modified by the following:

except global stability and bearing capacity.

do not negatively impact the wall system.

function properly through/beneath the wall without negatively impacting the wall system.

developing appropriate MSE soil reinforcement design details in the vicinity of the drainage features (pipes, catch basins, for example) within the reinforcement mass, and for the outlet point at the wall face.

MSE Retaining Walls – General Requirements

reinforcement by one of the following two measures:

steel sufficient for a corrosion rate of at least 0.80 mils per exposed surface per year after 16 years of corrosion protection service provided by the galvanized coating.

at least 30 mils thickness at least 2 ft below the base of the pavement section (below the bottom of the granular borrow layer). 1) Slope the geomembrane at a grade of 4 percent downwards towards the back of the reinforced mass (for example, away from the wall face) to a point at least 5 ft beyond the back of the soil reinforcement zone, and lap upward against the back side of the wall facing. 2) Design the metal soil reinforcement to provide sacrificial steel sufficient for the following minimum corrosion rates per exposed surface per year after 16 years of corrosion protection service provided by the galvanized coating:

30 inch for single-stage walls, or 24 inch for two-stage walls to provide a coherent MSE reinforced soil mass.

walls founded on earth slopes as shown.

internally tied structures.

geosynthetic soil reinforcement when overlapping.

corner and after the last column of panels where the full length of soil reinforcement can be placed. 1) Orient the soil reinforcement attached to the slip joints perpendicular to the slip joint panels. 2) Use soil reinforcement with the full design length.

the MSE retaining wall drawings

MSE Retaining Walls – General Requirements

where the soil reinforcement conflicts with obstructions in the wall soil reinforcement zone, such as piles, drilled shafts, guardrail posts, catch basins, drop inlets, and culverts:

additional load that would have been carried by the severed reinforcement.

transferring loads from the soil reinforcement on one side of the obstruction to the soil reinforcement on the other side of the obstruction.

reinforcement consists of discrete strips or bar mats rather than continuous sheets.

wall as shown using one of the following methods.

modular block unit, or coping).

steel plate to the wall face. 1) Completely remove excess material from the outline of each character. 2) Hot dip galvanize the plate after cutting the numbers into the plate.

and at 500 ft intervals.

PART 3 EXECUTION Not Used

END OF SECTION

MSE Retaining Walls – General Requirements