219.02 Materials.
of the material as required, placing the material in the areas designated, and for all equipment, tools, labor, and incidentals necessary to c omplete the work.
4.Pneumatic Concrete Blanket . The accepted area treated under this item will be paid for at the contract unit price bid per square yard {square meter} which shall be payment in full for the pneumatic concrete blanket complete in place an d includes preparation of the surface to be treated, furnishing all materials, installation of wire reinforcement, its accessories and anchor bolts, placement of the pneumatic concrete, and for all equipment, tools, labor, and incidentals necessary to comp lete the work.
b.Payment will be made under Item No .: 217-A Rock Bolting, 1" {25 mm} Slotted - per linear foot {meter} 217-B Rock Bolting, 5/8" {16 mm} Headed - per linear foot {meter} 217-C Rock Bolting, 3/4" {19 mm} Headed - per linear foot {meter} 217-D Rock Bolting, 7/8" {22 mm} Headed - per linear foot {meter} 217-E Seam Sealant - per cubic yard {cubic meter} 217-F Asphalt Surfacing - per gallon {liter} 217-G Pneumatic Concrete Blanket, ___ inches {mm} thick - per square yard {square meter} LANDSLIDE CORRECTIONS
219.01 Description.
This Section shall cover the work of correcting a landslide in an existing roadway slope within the designated areas shown on the plans or directed by the Engineer, all in accordance with the details shown on the plans or noted in this provision.
219.02 Materials.
Materials furnished for use shall conform to the appropriate requirements of the Standard Specifications for the type work performed or noted herein.
a.Geote xtile Filter . A geotextile to be used as a special underdrain shall meet the requirements of plan details, AASHTO M 288 for Subsurface Drainage Geotextile, Class 2, and Section 810 of these specifications. The geotextile shall be selected from List II -3, of the Department's manual titled "Materials, Sources, and Devices With Special Acceptance Requirements". Information concerning this list is given in Subarticle 106.01(f) and ALDOT -355.
b.Horizontal Drainage Pipe . The drainage pipe shall be PVC, Schedule 80, Type I or II, or Schedule 120 conforming to the requirements given in ASTM D 1785. The I.D. of the pipe shall be 1.5 inches {38 mm} unless noted otherwise on the plans. The pipe shall be furnished in lengths suitable for use with the drilling equipment approved for use. The ends of the pipe shall be machined to provide a smooth wall slip coupling when joined using appropriate solvent welding material thus precluding the use of conventional slip couplings. Fittings necessary for the outfall connections outside the drilling limits shall be PVC, Schedule 80, Type I or II, or Schedule 120 fittings having a burst strength equal to or greater than the pipe noted herein. All pipe and fitting connections shall utilize solvent weld joints. Slotted pipe shall be furnished unless noted otherwise on the plans. Slotted pipe shall have two rows of slots circumferentially cut 120 degrees apart. The average configuration shall be 46 slots per row, per foot {300 m m} with a maximum 0.010 inch {0.25 mm} slot opening when used in a silty or clay soil or 42 slots per row, per foot {300 mm} with a maximum 0.050 inch {1.3 mm} slot opening when used in a granular material. The configuration and the slot opening size shall be as shown on the plans.
c.Rock Buttress Material . Unless otherwise noted on the plans, rock buttress material shall be sandstone, limestone, dolomite, or granite free of dirt and debris. Rock buttress material shall have the physical properties for so undness, wear resistance and limited deleterious material content given in Section 814 for riprap.
219.03 Construction Requirements.
No more than 10 % of the rocks used for the main buttress construction shall have a weight over 500 pounds. At least 50 % shall have a weight over 80 pounds. No more than 10 % shall have a weight under 10 pounds. Oversize rocks may be allowed by the Engineer if spaced to permit filling and densification of the buttress. Rock used for choking shall pass a 4 inch {100 mm} screen and shall be no more than 10 % of the total rock required for the buttress. Acceptance of the gradation will be by visual inspection by the Engineer at either the source of the rock or at the project site. Any difference of opinion between the Engineer and the Contractor about the accept ability of the gradation shall be resolved by sampling and testing the rock in accordance with the method provided in ALDOT -239. The equipment, labor and sorting site for this procedure shall be provided by the Contractor at no cost to the Department.
219.03 Construction Requirements.
a.General . In general, the work necessary to correct a landslide is dependent upon the in situ conditions and extent of damage existing at each site and will vary according to the details shown on the plans. Basic procedures may require any combination of the following work items:
1.Excavation for the removal of loose or unwanted material. Normally, Unclassified Excavation as provided in Section 210 will apply unless otherwise noted by plan details.
2.Construction of paved flumes, installation of underdrain systems (Standard Underdrain as provided in Section 606 or Special Underdrain as noted herein or detailed in the plans), or other methods of removing surface or ground water from the area.
3.Construction of retaining str uctures (Standard Retaining Wall, Mechanically Stabilized Earth Wall, or Rock Buttress) as noted by plan details to stop slippage of slope material.
4.Restoration of back slope or front slope to a designated slope angle utilizing removed material, ordinary or special borrow material as designated by the plans. This work requires the preparation of the surface by rolling or otherwise compacting the area as directed to receive the backfill material. The backfill material shall be placed in the same manner as prescribed in Subarticle 210.03(d) for embankment.
5.Restoration of the erosion control over the repaired area as prescribed by the appropriate erosion control items provided in the contract.
b.Excavation . The area designated for treatment shall be exc avated to the depth indicated by the plans or directed to remove loose or otherwise unacceptable material. Removed material designated for re -use shall be stockpiled on approved areas; material not designated for re -use shall be disposed of as required in Article 210.05. Unless stockpile areas are designated on plan details, the Contractor shall provide, at his expense, satisfactory storage areas outside of the right of way limits.
c.Drainage Systems .
1.Surface drainage systems, when required, will be cl assified, paid for, and constructed under the appropriate item for such provided in the contract (reference Sections 610, 614, 615, 616, and 654).
2.Underdrain systems, when required, will be one of the following classifications as indicated by the plan details.
a.Standard underdrain - constructed and paid for under the provisions of Section 606.
b.Special underdrains - constructed in accordance with the details provided in the plans for size, shape, and content.
c.Special Filter Blanket - constructed i n accordance with the details provided in the plans, specifications, or as directed by the Engineer for size, shape, content, and type. If an aggregate blanket is required, the type and size of aggregate shall be as designated on the plans. The geotextile filter shall be placed in the manner and at the locations shown in the plans or as directed by the Engineer. At the time of installation, the geotextile shall be rejected if it has defects, rips, holes, flaws, deterioration, or damage incurred during manufacture, transportation, or storage. The geotextile shall be protected at all times during construction from contamination by surface runoff and any geotextile so contaminated shall be removed and replaced with uncontaminated geotextile. Any geotextil e damaged during its installation or during placement of backfill material shall be replaced by the Contractor at no additional cost to the State. The work shall be scheduled so that 14 days
219.03 Construction Requirements.
does not expire between placement of the geotextile and the cover ing of the geotextile with backfill. Backfill aggregate shall not be dropped on the geotextile from a height greater than 1 foot {300 mm}. Greater drop heights will be permitted if the Contractor provides a cushioning layer of sand on top of the geotextile before dumping of any stone. The combination of drop height for stone and sand cushion layer thickness to be approved must be demonstrated to not puncture or damage the geotextile. No measurement or separate payment shall be made for a sand cushion layer placed for the purpose of allowing an increased drop height of stone. Any damage to the geotextile during placement of aggregate shall be corrected prior to proceeding with the work.
d.Horizontal Drains - constructed in accordance with the following detai ls at locations, etc. shown on the plans or directed.
1.Horizontal drains shall cover the work of drilling appropriate size horizontal holes (angle and slope designated on plans) into backslope or frontslope and the installation of a designated size of s lotted PVC drainage pipe to facilitate drainage of ground water.
2.The installation procedure requires the holes be drilled with rotary drilling equipment capable of providing 3 inch {75 mm} to six inch {150 mm} diameter holes up to 600 feet {180 m} in length to the designated lines and grades through soil and rock formations.
3.The drilling equipment shall allow the installation operation to be accomplished by inserting the plastic drain inside the drill hole the full length of the drill hole.
4.The installation operation of the drain pipe shall be done in such a manner that the drain pipe will be cemented together where necessary to form a continuous tube and will not be telescoped or damaged to the extent that its drainage efficiency will be impair ed when completed.
5.The entrance end of the pipe shall be plugged with a rounded or pointed extension. The space between the drilled hole and the pipe shall be tightly plugged with earth for a length of at least 2 feet {600 mm} at the outlet end of the hole.
6.Water used for drilling and water developed during drilling operations shall be disposed of by the Contractor in such a manner that no damage will result to the work.
7.Unslotted PVC pipe approximately 10 feet {3 m} in length, shall be provided at the mouth of the drain to collector structure.
d.Slope Retaining Structures .
1.Retaining walls (cast -in-place or precast), if required, shall be constructed, measured, and paid for as provided in the appropriate Section of the Specifications.
2.Rock buttress, if required, shall be constructed, etc., in accordance with the following requirements:
a.General. The construction, in general, consists of the excavation of a trench, preparation of a bedding to receive a rock buttress and the construction o f a rock buttress to the line, grades, and slopes detailed on the plans.
b.Excavation of Trench. The excavation necessary to prepare the trench to the line, grades, slopes, and section shown on the plans or directed shall be classified and paid for under the Item of Unclassified Excavation or as provided on the plans.
c.Preparation of Trench Bed. The preparation of the trench bed shall be as detailed on the plans. Special bedding, if required, will be noted on the plans. Materials used in the special bedding shall conform to the specified sections of the Standard Specifications and will be paid for under the appropriate pay item for the materials used.
d.Rock Buttress. The rock buttress shall be placed in the prepared trench to the slopes shown on the p lans or directed by the Engineer. Choking material shall be provided when needed to sufficiently fill the voids to allow for traversing by truck or as a filter layer between the rock buttress and any required
219.04 Method of Measurement.
embankment materials. Densification of the rock backfill will be required as directed by the Engineer but density testing will not be required. Furnishing of the rock for the construction of the buttress shall be the responsibility of the Contractor. If permission is given to use any material outside r egular excavation limits within the right of way, it will be paid for only once under the appropriate pay item provided by this Section.
e.Construction Requirements for Geotextiles . Exposure of geotextiles to the elements between lay down and cover shall be a maximum of 14 days to minimize damage potential. The geotextile shall be placed and anchored on a smooth graded surface approved by the Engineer. The geotextile shall be placed in such a manner that placement of the overlying materials will not exces sively stretch or tear the geotextile. Anchoring of the terminal ends of the geotextiles shall be accomplished through the use of key trenches or aprons at the crest and toe of the back slope of the buttress or as specified on the plans. Successive geotext ile sheets shall be overlapped in such a manner that the upslope sheet is placed over the downslope sheet or upstream over downstream. In underwater applications, the geotextile and required thickness of backfill material shall be placed the same day. The backfill placement shall begin at the toe and proceed up the slope. Riprap and heavy stone filling shall not be dropped onto the geotextile from the height of more than 1 foot {300 mm}. Smaller sizes of stone filling shall not be dropped onto the geotextil e from a height exceeding 3 feet {1 m}. Any geotextile damaged during placement shall be replaced as directed by the Engineer at no additional cost to the State. The geotextile shall be joined by either sewing or overlapping as outlined in Article 608.05 o f these specifications. All seams shall be subject to the approval of the Engineer. Overlapped seams shall have a minimum overlap of 12 inches {300 mm} except where placed under water where the overlap shall be a minimum of 3 feet {1 m}. A geotextile patch placed over a damaged area shall be extended 3 feet {1 m} beyond the perimeter of the tear or damage.
f.Restoration of Slide Slope . Restoration of slide slope (front or back) shall consist of preparing the area to receive the replacement material by the shaping and compaction of the area as prescribed in Subarticle 210.03(d) for embankments. The material in place shall be compacted as noted in the plan details or directed by the Engineer. The backfill material may be the material previousl y removed, ordinary borrow, or special backfill material of the type designated in the plans or proposal. Said backfill shall be placed in layers and compacted as prescribed in Section 210 or noted by plan details. Erosion control items provided in the pla ns shall be used to re -establish the ground cover damaged or destroyed by the landslide or the restoration work.
219.04 Method of Measurement.
a.General Item . Construction items not specifically provided in this Section will be classified, measured, and paid for under the respective pay items for such work provided in the contract.
b.Rock Buttress for Landslide Correction . The Item of Rock Buttress for Landslide Correction, when provided in the plans or proposal, will be the weight {mass} of rock used i n construction of the buttress, measured on approved scales. Measurement of any special bedding, if required, will be as specified for the respective pay item used for bedding.
c.Special Underdrain . The Item of Special Underdrain, when provided in the co ntract, will be measured in linear feet {meters} of each special type detailed in the plans, along the center of each line or lateral, center to center of junctions and/or fittings.
d.Special Filter Blanket . The Item of Special Filter Blanket, when provi ded in the contract, will be measured in square yards {square meters} to the nearest 0.1 square yard {0.1 m²}, complete in place, for the material placed and accepted.
219.05 Basis of Payment.
e.Horizontal Drains . Horizontal drains will be measured by the linear foot {meter} of drain pipe installed in the holes drilled, including the extension necessary to discharge into the collector structure.
f.Special Backfill for Slide Correction .
1.When the item of special backfill for slide correction per ton {metric ton} is provided in the contract, the material ordered and accepted will be measured in tons {metric tons} on approved scales.
2.When the item of special backfill for slide correction per cubic yard in place {cubic meter} is provided in the contract, the accepted volume of backfill will be measured in cubic yards {cubic meters} complete in place by the cross section and average end area method. Cross sections shall be taken of the material in its original position, whether from a borrow pit, stockpile, or other approved sour ce, before placing of the backfill and re- cross sectioned after placing the backfill. The volume computed between these cross sections shall be the volume of backfill.
219.05 Basis of Payment.
a.Unit Price Coverage .
1.When the Item of Rock Buttress for Landslide Correction is provided in the plans or proposal, the accepted weight {mass}, measured as noted above, will be paid for at the contract unit price bid. Said contract unit price bid shall be payment in full for furnishing and/or producing material, royalties, loading, hauling, placing, consolidating, shaping, and for all equipment, tools, labor, and incidentals necessary to complete the work.
2.The accepted Item of Special Underdrain, measured as noted above, will be paid for at the contract unit p rice bid per linear foot {meter}, which shall be full compensation for the underdrain complete in place. Said unit price includes excavation of the trench, backfill and compaction thereof, furnishing and installation of any pipe, fittings, geotextile filte r, or filler necessary thereto, furnishing and placing of a connection to an outfall pipe or collector structure, the disposal of excess material, and for all tools, equipment, labor, and incidentals necessary to complete this item of work.
3.The accepted Item of Special Filter Blanket, measured as noted above, will be paid for at the contract unit price bid per square yard {square meter}, which shall be full compensation for the item complete in place and includes the furnishing of all materials, preparat ion of the area to receive the filter blanket, installation of the blanket and for all equipment, tools, labor, and incidentals necessary to complete this item of work.
4.The accepted Item of Horizontal Drain, measured as noted above, will be paid for at the contract unit price per linear foot {meter}, which shall be full compensation for furnishing and installation of the drains complete in place and connected to the collector structure. Said unit price includes full compensation for furnishing all materi als, services, equipment, tools, labor, and incidentals necessary to complete this item of work.
5.The Items of Special Backfill for Landslide Correction, ordered, accepted, and measured as noted above, will be paid for at the appropriate unit price bid per ton {metric ton} or cubic yard {cubic meter}, complete in place, which shall be full compensation for the furnishing of the type material designated for preparation of the area to be treated, loading, hauling, placement, compaction, and dressing of the area to the designated slope and includes all equipment, tools, labor, and incidentals necessary to complete this item of work.
b.Payment will be made under Item No .: 219-A Rock Buttress for Landslide Correction - per ton {metric ton} 219-B Special Underdrain ___ inch {mm} Diameter - per linear foot {meter} 219-C Special Filter Blanket * - per square yard {square meter} 219-D Horizontal Drain ___ inch {mm} Diameter - per linear foot {meter} 219-E Special Backfill for Landslide Cor rection - per ton {metric ton} 219-F Special Backfill for Landslide Correction - per cubic yard {cubic meter} * Specify either Aggregate or Geotextile.
224.01 Description.
SECTION 224 TREATMENT OF LIME SINKS
224.01 Description.
The work under this Section shall cover the treatment required to correct conditions occurring when lime sinks are found within or adjacent to construction limits of the work. The application and extent of the treatment will be in accordance with plan details or as directed.
224.02 Materials.
Material furnished for use under this Section shall be of the quality and character noted on the plans or ordered by the Engineer, suitable for the purpose intended, and consistent with the requirements for such materials as may be noted in other parts of these Specifications.
224.03 Construction Requirements.
a.General . Choice of equipment to perform the work required under this Section shall in general be that of the Contractor provided such will produce the desired results within the limits directed by the Engineer.
b.Sequence of Work . To properly evaluate the limits of the corrective treatment required to effectively bridge a lime sink, the work shall be performed in the following sequence:
1.Exploration of the lime sink area to lo cate the sink hole will be as directed by the Engineer; the size of the exploratory excavation shall be kept to a minimum.
2.The sink hole, once located, shall be enlarged to the size and depth as directed by the Engineer to expose the solution cavity.
3.After exposing the solution cavity, it shall be plugged with a rock boulder or a plug of suitable material capable of sealing the cavity, yet maintaining proper ground water drainage.
4.After installation of the plug, a strata of selected material that will permit proper ground water drainage shall be placed to a depth of approximately one- half the excavated hole depth, but not in excess of 7 feet {2 m}. The material used for this "Special Backfill" shall be of the type shown on the plans or directed. Th is special backfill material shall be placed in approximately equal uniform layers, not to exceed 2 feet {600 mm} in thickness, for the depth specified or directed. No compaction or density tests will be required.
5.The remainder of the backfill for the l ime sink excavation shall then be constructed of Unclassified Excavation, Borrow, or other designated material in accordance with the requirements for Embankments as required in Section 210.
6.In the event a sink hole occurs in the immediate vicinity of t he finished subgrade elevation, the use of concrete seal may be directed. In such case the same process noted before shall be used up to the bottom elevation designated for the concrete seal. The concrete shall be Class A concrete of the thickness shown on the plans or as directed. Steel reinforcement, if required, will be as provided by the plans or as directed.
224.04 Method of Measurement.
a.Lime Sink Excavation . Measurement for this item will be in cubic yards {cubic meters} computed from field measurements of the material actually removed as directed.
b.Special Backfill for Lime Sink . Special backfill material, furnished as directed, will be measured in cubic yards {cubic meters}, loose measurement, or per ton {metric ton} in the transporting vehicle. The boulder or plug will be measured for payment as an estimated number of cubic yards {cubic meters} or an estimated tonnage {metric tonnage}.
c.Concrete Seal . When the use of a concrete seal is ordered, measurement will be made i n cubic yards {cubic meters} computed from field measurement of concrete actually placed. All reinforcement required will be measured in accordance with Section 502, Steel Reinforcement.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 138–142 of 934.