Township of Middle Smithfield, PA Construction Standards and Requirements

Whenever other Township ordinances and/or regulations impose more restrictive standards and/or requirements than those contained herein, such other ordinances and/or regulations shall be observed; otherwise, the standards and requirements of this chapter shall apply.

Where there are no applicable Township standards or requirements, the streets and roads shall be constructed in accordance with standards and requirements furnished by the Township Engineer and/or the Township Planning Commission consultant, the Pennsylvania Department of Transportation, the Pennsylvania Department of Environmental Protection or other applicable agencies.

Modifications. Middle Smithfield Township may, subject to appropriate conditions, modify the construction standards and requirements as follows to preserve the environment and to protect the public health, safety and general welfare:

Waive any standards or requirements which, in its opinion, are inappropriate because of specific site or design situations.

Require higher standards or requirements necessary, in its judgment, under certain unique site situations.

§ 162-20 Specific standards and requirements.

Clearing and grubbing. The street or road right-of-way shall be cleared and grubbed to the extent shown on the approved cross sections as follows:

All tree stumps, roots and other material deemed unsuitable shall be removed from the grading area.

All branches of trees which extend over the roadway shall be trimmed to attain a clear height of 20 feet above the cartway.

Within the areas where excavation is to be made, the ground shall be cleared of all living and/or dead trees, stumps, brush and other objectionable material. All embedded stumps or root mats shall be removed to a depth of not less than 12 inches below the subgrade or slope surfaces.

Within areas where embankment is to be made five feet or more in depth, trees and stumps shall be cut off as close to the ground as is practicable, but not to exceed six inches above the ground surface. Near the toe of embankment slopes, no stumps or trees shall extend above the existing ground level.

Where an embankment is less than five feet in depth, unless otherwise shown on the drawings or field conditions warrant special treatment, all trees, stumps, roots, brush, matted roots, debris, sod and vegetable matter within 10 feet of the edge of the pavement shall be removed and grubbed to a depth of not less than eight inches below the existing ground surface.

Voids created by the removal of stumps and roots shall be backfilled and thoroughly compacted.

Rocks and/or boulders shall be removed to a minimum of six inches below the finished subgrade.

Excavation. All cuts shall be excavated to the extent of the approved cross sections as follows:

Slopes shall be trimmed neatly to the lines and rate of slope indicated on the original or revised drawings and/or cross sections and the work left in a neat and acceptable condition. Slopes in cuts may be varied during construction, according to the type of material encountered, in order to obtain satisfactory stability.

All drilling and blasting shall be performed in a manner to complete the excavation to the required lines to produce the least disturbance to the material to be left in place.

Blasting shall be performed by a fully insured and licensed contractor and shall be at the entire risk and responsibility of the applicant and/or the contractor.

The excavated material shall be removed by a method which will permit the designed or revised slope lines to be neatly and acceptably trimmed to meet the existing conditions.

Embankments. All fills shall be constructed to the lines shown on the approved cross sections as follows:

The embankment foundation area shall be cleared and grubbed in accordance with Subsection A above.

Existing depression in embankment areas such as gullies and old stream channels shall be backfilled to the adjacent ground elevation in the same manner as specified for the foundation of embankments.

All material placed in embankments shall be reasonably free of organic material and any other objectionable material considered unsuitable for use in embankment construction.

Frozen material shall not be placed in embankments and embankment material shall not be placed on material frozen to a depth of three inches or more. If during construction the top of the embankment freezes to a depth of three inches or more, the frozen material shall be removed before additional material is placed.

Wet material or material containing moisture in excess of that percentage which will ensure satisfactory compaction shall not be placed in embankments, and embankment material shall not be placed on material that has become unstable due to excessive moisture.

Dry material or material containing insufficient moisture to obtain satisfactory compaction shall be moistened before compaction.

All embankment material, other than rock for wet areas as specified in § 162-18R(5) shall be placed in uniform horizontal layers of not more than a loose eight-inch depth for the full width of the cross section. Compaction will be determined based on nonmovement of the material under the compaction equipment.

Embankment material placed in areas inaccessible to the compaction equipment shall be placed in uniform loose layers not exceeding four inches in depth and compacted by means of mechanical tampers.

(9)

Rock shall, in general, be placed to form the base of embankments for the full width of the cross section as follows:

Rock shall be placed in uniform loose layers not exceeding in depth the approximate average size of the larger rock, but limited to a maximum depth of 36 inches. Oversize rock shall be reduced in size until it can be readily incorporated in a thirty-six-inch layer.

Rock shall not be dumped in final position but shall be distributed by blading or dozing in a manner that will ensure proper placement in the embankment so that voids, pockets and bridging will be reduced to a minimum.

(c)

The top layer of a rock embankment shall be limited to a maximum depth of 12 inches with all voids filled with smaller pieces, spalls or granular material.

(d)

Before rock is placed on compacted embankment constructed of other material, the top of the embankment shall be sloped from the center line to the sides at a rate of approximately one inch to the foot and shall be thoroughly compacted.

(10)

During construction, the top layer of compacted embankments shall be kept shaped and drained at all times.

(11)

Slopes shall be neatly trimmed to the lines shown on the drawings or as directed, and the finished work shall be left in a neat and acceptable condition.

Special rolling. This work shall consist of special rolling of embankment or subgrade, as deemed necessary and as specified or directed by the Township in accordance with the following specifications and in areas specified by the Township.

Approved pneumatic-tired equipment shall be used for special rolling and shall be such that the load may be varied from 30 to 50 tons.

When the special rolling of any area shows that area to be unstable, such an area shall be brought to satisfactory stability by additional compaction or by removal of unsuitable materials, replacement with suitable material and compaction.

The roller shall be operated in a systematic manner so that the number of passes over all areas can be readily determined and recorded. The roller shall normally be operated at a speed of not less than 2 1/2 miles per hour.

Special rolling shall be performed only in the presence of the Township Roadmaster, the Township Engineer and/or the Township Planning Commission consultant whose duty it will be to approve or disapprove the stability of the embankment and to recommend corrective measures.

Cross drainage and culvert pipe. Construction standards for all cross drainage and culvert pipe shall be as follows:

Pipe trenches shall have a minimum width of twice the outside diameter of the pipe.

Pipe trenches shall be excavated through natural ground, or where pipe structures are to be placed under embankment, the contractor shall, unless otherwise directed by the Township, complete the construction of the embankment to a minimum elevation of one foot above the elevation of the top of the pipe before excavating the pipe trench. Where running water is encountered and cannot be diverted, a temporary pipe shall be placed in the trench prior to constructing the embankment.

When rock or hard shale is encountered, it shall be excavated below the bottom of the pipe a minimum of eight inches and filled with suitably compacted material.

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 mechanically tamped in four-inch layers to a satisfactory density.

When indicated on the drawings or directed by the Township, the pipe shall be laid in a cradle constructed of Class B (5,000 pound) concrete and reinforced when directed.

All pipe shall be laid carefully, bells upgrade, spigot ends fully entered into adjacent hub and true to line and grade.

All pipe shall be laid with cemented joints, except the interlocking style and pipe joined with bands.

Before succeeding sections of pipe are placed, the lower half of the joint shall be plastered with approved cement mortar to bring the inner surface of the abutting pipe flush and even. The cement mortar shall be composed of one part of cement and two parts of sand mixed with a sufficient quantity of water to form a plastic mortar.

(c)

The outside of the joint shall be overfilled with cement mortar to form a bead around the pipe.

(d)

The inside of the pipe shall be wiped clean and finished smoothly.

When pipes are protected by endwalls or connected with drainage structures, the exposed ends of the pipe shall be placed or cut off flush with the face of the structure.

Where pipe culverts are constructed in conjunction with existing drainage structures, provision shall be made for satisfactory connections.

(9)

After a pipe is laid, the trench shall be backfilled in four-inch layers with suitable material and thoroughly compacted under the haunches and along the sides with mechanical tampers or other approved methods.

Subgrade drains. Subgrade drains shall consist of a trench under the base filled with coarse aggregate and extending through the shoulder area and beyond to a suitable outlet and shall be constructed as follows:

The trenches for these drains shall have a minimum width of 15 inches and a minimum depth of six inches under the base course.

The bottom of the trench shall have a minimum slope of 1/4 inch per foot under the base and 1/2 inch per foot under the shoulder area.

The trenches shall be placed at right angles or at a skew with the roadway center line as directed.

The trench under the base course shall be filled with aggregate to the elevation of the subgrade and shall extend the full width of the base.

The outlet ends of all subgrade drains shall be marked with appropriate stakes and must be kept open at all times during construction and until final acceptance.

Subgrade drains shall be constructed as indicated in Figure C-6[1] at locations noted on the drawings and where deemed necessary by the Township.

[1]

Editor's Note: Figure C-6 is included at the end of this chapter.

Pipe underdrains. Pipe underdrains shall consist of a trench in which a pipe of the diameter specified shall be laid and the trench filled with Type I or Type II backfill.

Type I backfill shall consist of coarse aggregate to a depth indicated and the top of the trench filled with suitable soil.

Type II backfill shall consist of coarse aggregate covered with fine aggregate to the depth indicated and the top of the trench filled with suitable soil.

The pipe underdrain shall be placed after rough grading is completed, but before the base course is placed, except as otherwise directed by the Township.

The trench shall be excavated carefully, true to lines and grades and to a minimum depth of 30 inches unless otherwise indicated on the drawings, and the bottom of the trench shall be 15 inches wide.

A satisfactory outlet for pipe underdrain shall be provided.

Type I backfill shall be placed where trench excavation is in rock or shale or where specified or directed by the Township.

Type II backfill shall be placed where trench excavation is in soil or where specified or directed by the Township.

Where underdrains are constructed to join with existing drainage structures, provision shall be made for satisfactory connections as required.

(9)

Pipe underdrains shall be constructed as indicated in Figure C-5[2] except where a special design is indicated or specified by the Township.

[2]

Editor's Note: Figure C-5 is included at the end of this chapter.

Pipe underdrain outlets. Pipe underdrain outlets shall be pipe of the diameter specified, laid in a trench and backfilled with soil and the outlet ends protected with concrete endwalls. (See Figure C-6.[3])

Outlet pipe shall be first quality plain cement concrete pipe, unperforated corrugated metal pipe or equal.

The joints of the concrete pipe shall be filled with mortar composed of one part cement and two parts sand.

Pipe for outlets shall be of the same material as the pipe of the adjoining underdrain.

When outlets are constructed to join existing drainage structures, provisions shall be made for satisfactory outlet connections.

[3]

Editor's Note: Figure C-6 is included at the end of this chapter.

Subgrade. Subgrade shall consist of the preparation of the top surface of the roadbed to accommodate the placement of the base and shoulders in accordance with the following standards and in close conformity to the lines, grades and widths shown on the drawings and cross sections.

The design and construction of the roadbed shall take cognizance of the supporting capabilities of the subgrade, with particular attention to those soils which are subject to frost heave.

Unsuitable soils shall be removed and replaced, drained or otherwise stabilized to provide adequate support for the roadbed and anticipated loads.

The graded roadbed shall be formed to the established subgrade elevation and cross section and thoroughly compacted.

The subgrade shall be provided for the full width of the base course and shoulder area.

Compaction will be determined based on nonmovement of the material under compaction equipment.

Any subgrade which displays pronounced elasticity or deformation under compaction equipment shall not be allowed. When stability cannot be obtained, the material in the area shall be excavated to a depth so that, when replaced and recompacted, the subgrade will have the required stability.

The subgrade shall be protected and maintained at all times. Any unsatisfactory areas shall be reshaped and recompacted prior to the placement of the base and shoulder material.

Engineering stakeout of roadway. A stakeout of the proposed roadway shall be set to guide the contractor and to give the Township a method of checking lines and grades to assure the road is built in conformity with the drawings and cross sections. This stakeout for the different operations shall be as follows:

Stakes for clearing and grubbing shall be set where side slopes of cut or fill meet the natural ground, making sure all the slopes, including the rounding at the top of cuts and ditches at the bottom of fills, are included.

Stakes for grading operations shall be set to show proposed cuts and fills prior to starting the grading operation.

Road center lines or base lines shall be staked on the roadbed conforming to the drawings.

Stakes shall be placed on both edges of the proposed pavement, stakes to be offset at least one foot.

(c)

Stakes shall be placed on at least fifty-foot stations.

If it is deemed necessary or desirable by the Township, a final layout of the roadway shall be done when the paving is completed by marking on the pavement at even fifty-foot stations the center line as designated on the drawings. Stations shall be marked using PK nails and orange patch flagging with the station numbers either painted on the pavement or marked on offset stakes.

Crushed aggregate base course. The base course shall consist of construction of a layer or layers of crushed aggregate or other approved material on a prepared subgrade in accordance with the following standards and in close conformity to the lines, grades, widths and depths shown on the approved drawings and cross sections.

Base material shall be placed in layers of uniform depth not exceeding eight inches in compacted depth.

Base material shall not be placed on soft, muddy or frozen areas, nor until all irregularities in the prepared subgrade, including soft areas in the foundation, have been satisfactorily corrected.

Unstable base conditions which develop ahead of the paving operation shall be satisfactorily corrected by scarifying, reshaping and recompacting or replacement as required.

When required by the Township, crown templates, string lines and straight edges shall be furnished and used to control the finished elevations and smoothness of the base course.

The base material shall be maintained in a moist condition during hauling, placing and compacting.

The base material shall be deposited on the prepared subgrade by means of mechanical spreaders in a manner which will not cause segregation.

In the event that the base material fails, after placement, to compact to sufficient density, moisture may be added to obtain compaction. If compaction is not obtained, the material shall be remixed, reconstructed or removed and replaced.

The uniformly spread material shall be compacted by means of a ten-ton roller or its equivalent. Compaction will be determined based on nonmovement of the material under the compaction equipment.