2.3.3 Minimum sight distance.
Proper sight distances shall be provided for both horizontal and vertical alignment, measured along the center line Minimum sight distances shall be five hundred (500) feet for collector streets, four hundred (400) feet for primary streets and two hundred fifty (250) feet for-secondary streets Proper sight lines shall be maintained at all intersections Measured along the center line, there shall be a clear sight triangle of seventy-five (75) feet from the point of intersection for fifty-foot rights-of-way and one hundred thirty (130) feet for sixty-foot and eighty-foot rights-of-way This sight line shall be indicated on all plans of street alignment No existing or proposed structures or plantings, the highest point of which is two (2) feet above road center line, shall be permitted in this area
2.3.4 Leveling area to be provided at intersection approaches.
Intersections shall be approached from all sides by leveling areas Where the grade exceeds seven percent (7%), such leveling areas shall have a minimum length of fifty (50) feet measured from the edge of pavement of the transverse street within which no grade shall exceed four percent (4%)
2.3.5 Vertical curves.
At changes in grade of more than one percent (1%) vertical curves shall be used The length of the curve shall be a minimum of one hundred (100) feet on collector and primary streets and a minimum of fifty (50) feet on secondary streets for every one-percent change in grade Vertical alignment shall conform as much as practical to the existing contour of ground within the limitations hereinabove stipulated
2.3.6 Tangent lengths between curves.
In horizontal alignment of streets a minimum tangent length measured at the center line of one hundred (100) feet shall be provided on collector and primary streets between the P T of the first curve and the P C of the second curve, unless otherwise approved by the Engineer. In no case shall two (2) curves in reverse direction be joined together without the minimum one-hundred-foot tangent length provided for the above two (2) classifications of streets Secondary streets shall be excepted from the above stipulated requirement of minimum tangent lengths between curves and shall be as required or approved by the Engineer
A.minimum grade of one percent (1%) shall be established on all primary or secondary streets and a minimum grade of one-half of one percent (1/2 of 1%) shall be established for all collector streets upon prior approval by the Engineer.
Maximum grades of five percent (5%) shall generally apply In exceptionally hilly areas, a maximum grade of six percent (6%) on collector and primary streets, and ten percent (10%) on secondary streets for a maximum distance of one thousand five hundred (1,500) feet will be permitted, subject to approval by the Engineer.
2.3.9 Maximum grade limits for a turnaround.
Maximum grades within one hundred (100) feet of the outer perimeter of a turnaround shall not exceed three percent (3%) as measured along the center line of the street
2.3.10 Restriction of grade on horizontal curves.
A.combination of minimum radius horizontal curves and maximum grades will not be approved
2.3.11 Normal street crown requirements.
A.normal crown shall be provided on all streets, not superelevated, of five-sixteenths (5/is) inch per foot straight slope extending in cross section from edge of pavement to center line or from edge of pavement to medial edge, whichever will apply, symmetrical to the center line
2.3.12 Restriction of intersections with through highways.
Whenever practicable, the number of intersections with through highways shall be kept to a minimum, and shall be located at least one thousand (1,000) feet apart
2.3.13 Streets to intersect at right angles.
Whenever practicable, right-of-way lines shall intersect at right angles When secondary streets intersect primary or collector streets, the angle of intersection of the street center lines shall not be less than sixty degrees (60)
2.3.14 Curb radius returns to be provided.
Street curb intersections shall be rounded by a tangential arc with a minimum radius of twenty (20) feet for secondary streets and thirty (30) feet for intersections which incorporate primary or collector streets
2.3.15 Dedication of half streets prohibited.
Dedication of half streets at the perimeter of a new subdivision is prohibited If circumstances render this impracticable, adequate provision for the concurrent dedication of the remaining half of the street must be furnished by the subdivider Where there exists a half street in an adjoining subdivision, the remaining half shall be provided by the proposed development
2.3.16 Reserve strips controlling ingress or egress to streets prohibited.
Reserve strips controlling ingress and egress are prohibited When the subdivision adjoins unsubdivided acreage, new streets shall be provided through to the boundary lines of the development with temporary easements for turnarounds, or at the discretion of the Engineer, the entire width of the right-of-way may be paved for a distance of seventy-five (75) feet
2.3.17 Street names to be continuous where feasible.
Streets that are extensions of, or obviously in alignment with, existing named streets shall bear the names of the existing streets All street names shall be subject to the approval of the governing officials of the municipality within which they are located
2.3.18 Depressed curbs to be provided.
Whenever curbs are to be constructed across private driveways within residential areas or driveway approaches of ingress or egress from abutting industrial or commercial properties, the curb shall be depressed as shown on the standard detailed drawings of these specifications, unless otherwise directed by the municipal authorities (See Appendix C)
The minimum longitudinal length of depressed curb for private driveway crossings shall be twelve (12) feet and the maximum longitudinal length for driveway crossings in commercial or industrial areas shall be thirty-five (35) feet When required, and approved by the governing authorities, separated driveway approaches may be constructed for entrance and exit to abutting properties Such individual driveway approaches shall not exceed the maximum longitudinal length of thirty-five (35) feet of depressed curb at each driveway approach, and a standard curb section shall be constructed, as a separating curb between the driveways; conforming to the dimensions and details of the standard detailed drawings of these specifications
2.3.19 Long radius curbs preferred.
A.long radius curve shall be preferred in all cases to a series of short curves and tangents
3.1.1 Materials.
Unless otherwise approved or specified by the governing officials only new materials shall be incorporated in the work Materials shall conform, when applicable, to that specified by the Pennsylvania Department of Transportation and shall be obtained from suppliers who are listed within the current certified and approved list of suppliers of the Pennsylvania Department of Transportation
All materials furnished by the contractor to be incorporated in the work shall be subject to the inspection and approval of the governing officials No material shall be processed or fabricated for or delivered to the work without prior approval of the Engineer, except at the risk of the contractor As soon as possible after the contract has been executed, the contractor shall submit to the Engineer data relating to materials he proposes to furnish for the work Such data shall be in sufficient detail to enable the Engineer to identify the particular product in question and to form an opinion as to its conformity to the contract requirements Facilities and labor for the handling and inspection of all materials shall be furnished by the contractor Defective materials shall immediately be removed from the site of the work at the contractor's expense If the Engineer so requires, either prior to beginning or during the progress of the work, the contractor shall submit samples of the materials or such special tests as may be necessary to demonstrate that they conform to the specifications The contractor shall place his orders sufficiently early to permit consideration, inspection, testing and approval before the materials are necessary for incorporation in the work
3.1.2 Handling and distribution of materials.
The contractor shall, at his own expense, handle, haul, and distribute all materials and all surplus materials on the different portions of the work as required He shall provide suitable and adequate storage room for materials during the progress of the work and be responsible for any loss of or damage to materials furnished or accepted by him until the final acceptance of the work
3.1.3 Lines, grades and measurements.
The contractor shall make all measurements and check all dimensions necessary for the proper construction of the work called for by the drawings and specifications, and during the prosecution of the work he shall make all necessary measurements to prevent misfitting in said work, and he shall be responsible therefor and for the accurate construction of the entire work
3.1.4 Precautions during adverse weather.
During adverse weather, the contractor shall take all necessary precautions so that the work may be properly done and satisfactory in all respects When required, protection shall be provided by use of tarpaulins or other improved protective materials During cold weather, materials shall be preheated, if required, and the materials and adjacent structure in which they are to be incorporated shall be made and kept sufficiently warm so that a proper bond will take place and proper curing, aging or drying will result
3.1.5 Temporary-heat. If temporary heat is required for the protection of the work, the contractor shall provide and install approved heating apparatus and shall provide adequate and proper fuel and maintain fires as required Temporary heating apparatus shall be installed and operated in such manner that the finished work will not be damaged thereby
3.1.6 Water supply for construction.
All water used for concrete -work-and curing of -concrete-and all water used for other construction purposes shall be clean and free from acid, alkali and iron and from injurious amounts of vegetable matter and oil Untreated raw water will not be permitted for these purposes
3.1.7 Use of explosives.
In the event that blasting or the use of explosives are used during construction, approval and all necessary permits shall be obtained from the municipal authorities prior to its use The location, extent, purpose, tune and quantity of explosives to be used shall be subject to said approval Safety protection shall be as directed by the governing authorities
3.2.1 Open drainage ditches restricted
Only natural watercourses which are of sufficient size to come under the regulations of the Pennsylvania Department of Forests and Waters (i e., draining one-half-square-mile or more) shall be permitted to enter or flow through a developed subdivision within an open (nonconduit) channel All other drainage watercourses, channels or ditches shall be incorporated into a storm sewer system and shall flow through pipes from a point of intersection with the exterior boundary lines of a subdivision at its entrance to a point of intersection with the exterior boundary of the subdivision at its exit
3.2.2 Pipe foundation underdrain.
Intercepting underdrains shall be required at all locations in which subsurface water is encountered which may permeate or endanger the subgrade of the street Underdrains shall be required in all cuts three (3) feet deep and greater and in all other locations stipulated by the Engineer Pipe foundation underdrains shall parallel the established street grade to outlet in approved drainage structures Pipe foundation underdrain shall consist of a trench excavated to a minimum depth of twenty-four (24) inches below the underneath elevation of the curb and to the minimum width of eighteen (18) inches, in which a six-inch pipe underdrain shall be laid The trench shall be backfilled with Pennsylvania 2B Aggregate to its full depth around and above the laid pipe to the underneath elevation of the base course
(a) Materials The pipe shall be first-quality perforated vitrified clay, cradle-invert vitrified clay, cement concrete pipe or perforated coated corrugated metal pipe, except that cement concrete pipe and perforated corrugated metal pipe shall not be used where, in the opinion of the Engineer, acid water will be encountered
(b) Construction methods. The pipe underdrain shall be placed after rough grading is completed, but before the special subgrade, base course or wearing surface pavement have been placed, except as otherwise directed by the Engineer A layer of Pennsylvania 2B gravel two (2) inches in depth shall be tamped in the bottom of the trench as a foundation for the pipe Perforated vitrified clay pipe shall be a bell and spigot type carefully laid, bell ends upgrade, spigot ends fully entered into the adjacent bell and perforations shall be placed down Perforated corrugated metal pipe shall be jointed together with connecting bands securely bolted with approved galvanized bolts and perforations shall be placed down, unless otherwise specified Cement concrete pipe or cradle-invert vitrified clay pipe shall be plain end type with each length abutted against adjacent length All pipes shall be laid true to line and grade After the pipe is laid on its foundation, a backfill of 2B Aggregate is then placed If the length of pipe underdrain exceeds six hundred (600) feet in one (1) run, the minimum diameter of six (6) inches shall be increased to eight (8) inches beyond that point
3.2.3 Storm sewer pipe.
The minimum diameter of all storm sewer pipe shall be fifteen (15) inches, and the minimum grade shall be one-half of one percent (1/2 of 1%) Materials for storm sewer pipe shall conform to the standard culvert pipe designations of the Pennsylvania Department of Transportation specifications secured from sources approved by the municipal officials Storm sewer pipe shall be plain or reinforced concrete culvert pipe or full asphalt coated corrugated metal paved-invert pipe
3.2.4 Excavation for pipe trench.
The contractor shall make all necessary open trench excavation to line and grade herein specified or as directed by the Engineer Caution shall be taken to prevent excavation deeper than necessary, as pipe shall not be placed on filled material without approval of the Engineer
The contractor shall provide ample space in pipe trenches to permit proper laying of pipe and fittings Pipe trenches shall be excavated to the widths and using the methods as specified in Section 3.2 12 of these specifications
The contractor shall be responsible for properly supporting the sides of all excavation Such supports shall be adequate to fully protect workmen working within the trench, to maintain reasonably vertical trench walls, to prevent undue scuffing off of materials into the trench and to prevent damage to abutting property or structures
The contractor shall construct and maintain suitable barricades around all open excavation and shall maintain sufficient lights for said barricades to prevent accidents, or as directed by the municipal police force
The minimum depth of cover over the top of pipe laid in place shall be two and zero-tenths (2 0) feet for rigid pipe lad beneath unpaved surfaces or flexible-type pavements, and one and five tenths (15) feet for nonrigid pipe laid beneath unpaved surfaces or flexible-type pavements, as measured vertically between the outer top surface of the pipe and the under side of the wearing surface pavement or its projected elevation In no case shall this vertical measured dimension be less than one and five-tenths (1.5) feet.
If rock is encountered within the excavated trench, the trench shall be subcut to a minimum depth of four (4) inches beneath the lowest projection of the pipe barrel and backfilled with Pennsylvania 1B Aggregate to the spring line elevation of the pipe when laid The maximum size of any particles in the selected material shall be one-half (1/2) inch Excavation of the open trench shall be restricted to a maximum of six hundred (600) feet ahead of laying of pipe
3.2.5 Pipe laying.
The laying of pipe in finished trenches shall be commenced at the lowest point, so that the tongue or spigot ends point in the direction of flow
All pipes shall be laid in a dry trench with tongue or spigot ends fully entered into the adjacent groove or bell and true to the required lines and grades. Tongues and grooves or bell and spigots shall be satisfactorily cleaned before laying each section All joint work shall be done in an approved manner by skilled workmen to the end that the pipe when laid shall form a continuous pipeline with a smooth and uniform interior surface The pipe sections shall be satisfactorily jointed The tongue end of each section shall be inserted the proper distance into the groove to make a watertight and adequately sealed joint No gapping or irregular joints shall be acceptable in the work.
When unstable foundation material is found within the trench, the Engineer may direct that undercutting of the trench shall be performed and backfill to the established grade be made with suitable material, compacted and stabilized, to form the proper pipe bedding, or the Engineer may direct that a Class B concrete pipe saddle be placed throughout the unstable length of trench
When pipe is placed within a trench below the established water table, the Engineer may require that all joints be formed with a continuous ring rubber seal gasket or that a collar or mold of cement mortar, not less than one (1) inch thick and four (4) inches wide, shall be placed around the outside perimeter of (entirely encircling) the pipe at the joint of each section.
3.2.6 Backfilling of trenches.
All trenches and excavations shall be backfilled immediately after the pipes are laid, unless other protection of the pipe is necessary The backfilling material shall be selected earth, free from large lumps and stones having any dimension greater than two (2) inches, and thoroughly compacted under the haunches and along the sides with mechanical tampers or other approved methods as fast as placed up to a level above the top of the pipe The filling and tamping of the backfill shall be carried up evenly on both sides of the pipe, care being taken not to raise the pipe or move it off line during the operation
The remainder of the trench shall then be filled and compacted by tamping or rolling The backfill material shall be evenly spread in built-up layers not exceeding eight (8) inches before tamping or power rolling Care shall be taken that the material close to the bank, as well as other portions of the trench, shall be thoroughly compacted
Puddling or water flooding shall be restricted to consolidating the backfilling of sandy or gravelly materials No compacting shall be done when the material is too wet to be compacted properly If this method is used, the first flooding shall be applied after the backfilling has been compacted by tamping up to two (2) feet above the top of the pipes, and the second flooding during or after the subsequent filling of the trench An excess of water shall be avoided, in order to prevent disturbance of the earth under and around the pipes also, to prevent an undue excess of pressure upon them Walking or working on the completed pipeline, except as may be necessary in tamping or backfilling, shall not be permitted until the trench has been backfilled to a height of at least two (2) feet over the top of the pipes
The method of backfilling outlined in this section shall apply to all utilities and service lines contained within the right-of-way of all roads and streets
3.2.7 Seasonal limits.
No construction shall be done during unfavorable weather
3.2.8 Inlets.
Inlets shall conform to PennDOT type four-foot special and type six-foot special as shown on the standard detailed drawings of these specifications The work shall include all necessary excavations for the structures and their appurtenances, the construction of all foundations, all brick and concrete masonry, the setting of cast iron frames and wrought iron or structural steel gratings, backfilling of excavation areas and any other work necessary for their completion
All materials shall be procured from approved sources, and be of the design type approved by the Engineer All metal castings for frames and gratings shall conform to ASTM standards
Excavation shall be made to the required depth and the earth foundation material shall be stable and compacted to a firm even surface
The forms for the concrete structure shall be sufficiently rigid to prevent displacement or sagging between supports, and so constructed that the concrete will not be damaged by their removal. Forms shall be sufficiently tight to prevent leakage of mortar The contractor shall be entirely responsible for their adequacy
All forms shall be thoroughly cleaned and oiled before concrete is placed therein, with an approved nonstaining oil or liquid form coating
Forms for concrete surfaces exposed to view in the finished work shall be of plywood, sanded smooth and fitted with tight joints between panels
3.2.9 Inlet spacing.
Inlets shall generally be located at street intersections to intercept the stormwater before it reaches pedestrian crossings or at sag points of vertical curves in the street alignment which provides a natural point of ponding of surface stormwater
The interval between inlets serving stormwater runoff flow along the curb shall not exceed a maximum of one thousand (1,000) feet when located along any one (1) continuous curbline More frequent spacing shall be required when the entrance capacity of any individual inlet warrants closer spacing as determined by calculations which incorporate consideration to the area drained, intensity of rainfall, slope of grade, runoff coefficient of imperviousness and cross-sectional area of the gutter When inlets are used in a storm sewer system within the right-of-way limits of a street in lieu of manholes, the spacing of such inlets shall not exceed the maximum distance of four hundred fifty (450) feet along any one (1) continuous line
It is the intent of these specifications to stipulate and to regulate adequate street drainage for all normal expected stormwater flows, and to that end it shall be required that all construction shall conform to the lines and dimensions of the subdivision drainage plan or area drainage plan approved by the governing municipal authorities
The design discharge for use in determining gutter flow spacing of stormwater inlets and for pipe sizing of storm sewer shall be computed by the Rational Formula Q=AIR See § 130-24, Chapter 130, Subdivision and Land Development
The standard computation sheet of these specifications shall be the acceptable form for use in preparing drainage calculations for submission to the municipal governing officials for their approval
3.2.10 Manholes.
This item shall consist of the construction of manholes and appurtenances, and they shall be constructed to the lines and grades given and to the dimensions shown on the standard detailed drawings of these specifications The work shall include all necessary excavation for the structures and their appurtenances, all concrete, brick and concrete block masonry, the setting in place of all cast iron frames and covers, backfilling of all trenches and excavations and any other work necessary for their completion
All materials shall be procured from approved sources and be of the design type approved by the Engineer All metal frames and covers shall conform to ASTM standards and conform to the dimensions shown on the standard detailed drawings of these specifications
Excavation shall be made to the required depth, and the earth foundation material shall be stable and compacted to a firm even surface When the foundation material is found to be of waterbearing texture, the Engineer may require additional depth excavation to a more stable foundation material, backfilled to the prescribed foundation elevation with select material
Wood forms shall be constructed for all concrete structures The forms shall be so constructed that watertightness shall be maintained and braced and wired in such manner to prevent warping and expansion under the pressure of the loads contemplated during the placing of the concrete The forms shall be thoroughly cleaned prior to using and oiled to facilitate their removal The concrete when placed within the forms shall be restricted-to a-maximum of five-(5) feet of freedrop and-shall be spread and tamped or vibrated into place in such a manner as to eliminate honeycombing
Masonry for manholes shall consist of brick, precast concrete blocks or cement concrete
All brick for brick structures shall be thoroughly wet by immersion immediately before laying Every brick shall be laid in full mortar joints on bottom sides and end, which shall for each brick be formed in one (1) operation In no case are the joints to be made by grouting or by working in mortar after -laying-the-brick No-joint-shall exceed three-eighths (3/s) inch-in opening All joints on faces shall be trowel struck
All unfinished brick masonry shall be racked back or toothed, and when new work is joined to the unfinished portion, the latter must be thoroughly cleaned
Brick masonry of sides and arches shall be bonded and keyed, special care being exercised with each ring against too large a joint at the back All joints shall be normal to the section and all lipping of brick shall be carefully avoided
Precast concrete blocks shall be of the best quality and the sources of supply approved by the Engineer Each block shall be sound and free from cracks and other structural blemishes and shall conform to the proper radius designated by the Engineer
Precast concrete blocks shall be laid up in a manner that will ensure watertight joints and so laid in horizontal courses with vertical joints staggered in a full bed of mortar on bottom sides and end In general the procedure hereinbefore specified for brick masonry shall apply to the laying of precast concrete blocks
Precast reinforced concrete manhole sections shall be of the best quality and the sources of supply shall be approved by the Township Engineer Each section shall be sound and free of cracks and other structural defects and conform to the proper diameter and wall thickness designated by the Engineer Each joint shall be sealed with a rubber O-ring and cement mortar Precast manhole bases are prohibited
Cement mortar for masonry construction shall be made with portland cement and clean, sharp sand to the proportion of one (1) bag of cement to two (2) cubic feet of sand The sand shall be measured loose in a bucket, or some other suitable measure of known volume The cement and sand shall be thoroughly mixed when uniformly dry, then wetted with water to make a stiff paste which will be plastic under the trowel, but not so soft as to run after being placed, and shall be used before it has begun to stiffen Mortar that has once set shall not be remixed and used
Concrete for manholes shall be Class A concrete and shall be procured from suppliers who are listed within the current certified approved list of suppliers for the Pennsylvania Department of Transportation The concrete shall have a minimum allowable compressive strength of three thousand six hundred (3,600) pounds per square inch at twenty-eight (28) days and shall contain a minimum of six (6) bags of portland cement per cubic yard of concrete, and the maximum allowable water content shall be five and six-tenths (5 6) gallons per bag of cement, including the free water in the aggregate All concrete shall be a certified concrete by the supplier as to weight, proportioning of aggregates and water-cement ratio
Reinforcing steel shall be deformed bats conforming to the diameters and spacing as shown on the standard detailed drawings of these specifications
The manholes shall be plastered on the outside with a one-half-inch coat of mortar, as specified above for cement mortar, to which shall be added one-tenth (1/10) bag of an approved commercial brand of lines per bag of cement
No forms shall be removed from the foundation base slab or from the walls of a manhole within a minimum period of forty-eight (48) hours after the completion of each succeeding concrete pour No concrete shall be placed when the temperature is below forty-five degrees Fahrenheit (45 F ) without special approval of the Engineer
The cast iron manhole frames and covers shall be set on full mortar beds composed of one (1) part portland cement and two (2) parts of fine aggregate and set to the elevations shown or ordered Galvanized wrought iron steps shall be built into the walls of the manhole in a staggered pattern
Upon completion, subject to the approval of the Engineer, and after all forms have been removed, the manhole excavation area shall be backfilled to the lines and grades specified by the Engineer. The backfill shall be placed in suitable layers thoroughly compacted, uniformly brought up on all sides of the manhole Caution shall be directed to maintaining a compacted backfill without damage to the structure
3.2.11 Manhole location.
Manholes shall be located on a continuous storm sewer system at all abrupt changes of grade, at all locations where a transition in storm sewer pipe sizing is required, at all angle points exceeding fifteen degrees (15), and at all points of convergence of two (2) or more influent storm sewer mains The construction locations of manholes shall be as indicated on the subdivision drainage plan or area drainage plan approved by the governing municipal authorities
The maximum spacing of manholes serving a continuous storm sewer main shall be four hundred fifty (450) feet
3.2.12 Metal plate pipe culverts and pipe arches.
Metal plate pipe culverts and pipe arches shall be required when an existing watercourse is to be crossed over by a street
Generally a metal plate pipe culvert or pipe arch will be specified for such conditions when there is not sufficient cover for a circular pipe culvert or where aesthetic considerations are important
Metal plate pipe culverts and pipe arches shall consist of structural units of galvanized corrugated metal conforming to the PennDOT current specifications for metal plate pipe culverts, arches and pipe arches
Materials shall be procured from suppliers who are listed within the current certified and approved list of suppliers of the PennDOT.
(a) Construction methods shall consist of forming the bed and trench as hereinafter specified For pipe not exceeding sixty (60) inches inside diameter, the trench shall have a minimum width of twice the outside diameter of the pipe at the hub or band, except that for storm sewers entirely outside the pavement area, the width of the trench shall be not more than one (1) foot plus the outside diameter of the pipe at the bell or band For pipe more than sixty (60) inches inside diameter, the trench shall be six (6) feet plus the outside diameter of the pipe at the hub or band The trench shall be excavated through natural ground, or where the pipe structures are to be placed under the embankment the contractor shall complete the construction of the embankment to a minimum elevation of one (1) foot above the elevation of the top of the pipe before placing Where running water is encountered and cannot be diverted, a temporary pipe shall be placed in the trench prior to constructing the embankment
(b) When firm but slightly yielding material is encountered in the bottom of the trench, it shall be shaped carefully to fit the bottom of the pipe for a depth of at least one-tenth (1/10) the outside diameter of the pipe
(c) When rock or hard shale is encountered, it shall be excavated below the bottom of the pipe one-half (1/2) inch for each foot of embankment over the pipe, but not less than eight (8) inches, and filled with suitable compacted material The bed shall be shaped as described in item (a) above
(d) When the material encountered is unstable, it shall be entirely removed under the pipe for the full width of the trench or as otherwise required for the particular condition and replaced with suitable material and the bed shaped as described in item (a) above
(e) When directed by the Engineer, the pipe shall be bedded in a cradle constructed of Class B concrete, reinforced as directed, to the dimensions approved by the Engineer
The plates, except the haunch plates for pipe arches, shall be placed shingle-wise so that the flow of water will be over the edge of the plate and not against it The haunch plates may require placement inside or outside of adjacent launch plates Only sufficient bolts shall be placed to hold the plates in position Bolts and nuts shall not be drawn tight until the structure is completely assembled The bottom two (2) rows of bolts may-be-placed with the threaded end inside the-structure to facilitate tightening On other seam the bolts shall be placed alternately so that the nuts will always be on the crests of corrugations, first inside, then outside the culvert
Struts for pipe arches shall be placed to retain the size of the pipe arch Strutting shall be carried uniformly from end to end of pipe and pipe arches without endwalls
The pipe shall be deformed the required amount by means of suitable jacks The method of jacking shall meet with the approval of the Engineer A tolerance of twenty-five percent (25%) above and below the specified amount will be permitted
When directed by the Engineer, metal plate pipe culverts and pipe arches shall be fully asphalt coated and invert paved
(f) Backfilling around metal plate pipe culverts and pipe arches shall be performed after the plates have been satisfactorily erected, and suitable fill material around the pipe and pipe arch shall be placed to a height not exceeding the outside diameter of the pipe in four-inch layers, alternately on each side of the pipe or pipe arch, thoroughly but not excessively compacted with mechanical tampers Great care shall be used to obtain thorough compaction under the haunches and along the sides to the top of the pipe
The remainder of the backfill shall be placed and rolled in layers of not more than eight (8) inches of loose material to the full width of the cross section
Puddling of the fill material will not be permitted
Any fill material which causes excessive distortion of the plates shall be removed, plates braced into correct position and fill material replaced The bracing shall be removed as directed by the Engineer
The skew angle shall not exceed forty-five degrees (45) for metal plate pipe or pipe arches When the skew angle for arches is more than fifteen degrees (15), the length of the structure shall be such that no portion of the live load will be carried by the cut portion of the arch end When right-of-way or other conditions do not permit this required length, then the cut end shall be supported by a rigid headwall designed to meet the conditions and the end plates shall be anchored to this headwall
3.2.13 Endwalls required.
This item shall consist of the construction of endwalls of the types specified in the Endwalls Drawing of these specifications 27 and shall be required at the ends of all stormwater conveyance structures The work shall include excavation, forming and placement of concrete in order to build the structure as indicated Generally these structures will be built of Class B concrete, except in special cases where rubble masonry may be used by permission of the Township Engineer
Concrete for endwalls shall be as specified in Section 3 3 7 of these specifications Special care shall be used by the design engineer to select the proper endwall to fit the condition.
3.2.14 Storm and sanitary sewer easements.
Within all subdivisions in which off-street storm or sanitary sewers are to be constricted or are anticipated for future construction, a twenty-foot maintenance easement shall be provided and such easement shown in the subdivision plans which are submitted to the governing municipal authorities for their approval Existing watercourses which are under the jurisdiction-of -the Pennsylvania-Department of Forests and Waters into which stormwater is permitted to be deposited shall not require an easement within or adjacent to its banks However, all storm sewers so placed to feed into said existing watercourse shall require the stipulated maintenance easement. Sanitary sewers which parallel or are adjacent to such watercourses shall be provided with the stipulated easement
Whenever practicable the maintenance easement shall be parallel with and conjunctive to property boundary lines of the subdivision
