585STONE FILL

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1This work shall consist of furnishing and placing a dense stone fill at the locations shown on the plans or ordered. Stone Fill

is typically required for stability of embankment fill and soil cut slopes steeper than 2 horizontal to 1 vertical, although slopes at a flatter grade with water seepage or subject to submergence, such as in water quality treatment basins, could require stone fill. Stone fill is also used for erosion protection at pipe outlets, in drainage channels and for other drainage structures where expected water flows and velocities may require it. Materials

2.1Stone for stone fill shall be approved quarry stone, or broken rock of a hard, sound, and durable quality. The stones and

spalls shall be so graded as to produce a dense fill with a minimum of voids. 2.1.1 Class A stone shall be irregular in shape with approximately 50 percent of the mass having a minimum volume of 12 ft3, approximately 30 percent of the mass ranging between 3 and 12 ft 3, approximately 10 percent of the mass ranging between 1 and 3 ft3, and the remainder of the mass composed of spalls. 2.1.2 Class B stone shall be irregular in shape with approximately 50 percent of the mass having a minimum volume of 3 ft3, approximately 40 percent of the mass ranging between 1 and 3 ft3, and the remainder of the mass composed of spalls. 2.1.3 Class C stone shall consist of clean, durable fragments of ledge rock of uniform quality, reasonably free from thin or elongated pieces. The stone shall be made from rock which is free from topsoil an d other organic material. The stone shall be graded as follows: Sieve Size Percentage by Weight Passing 12 in 100 4 in 50 - 90 1-1/2 in 0 - 30 3/4 in 0 - 10

2.1.4 Class D stone shall conform to Table 520-3 - Coarse Aggregate, Standard Stone Size No. 467. 2.1.5 Spalls for filling voids shall be stones or broken rock ranging downward from a maximum size of 1 ft3.

2.2Gravel blanket material shall conform to 209.2.1.2.

2.3Geotextile shall conform to Section 593.

Construction Requirements

3.1Stones and spalls for stone fill shall be deposited and graded to eliminate voids and obtain a dense mass throughout the

course. The spalls shall be tamped into place using an equipment bucket or other approved method. 3.1.1 When stone fill is placed on a slope, the stones shall be deposited in such a manner as not to dislodge the underlying material unnecessarily. 3.1.2 When stone fill is placed on a geotextile, it shall be deposited in a manner to maintain the integrity of the geotextile.

3.2When gravel blanket is shown or ordered, the gravel shall be placed in layers not exceeding 12 ” in depth unless otherwise

ordered.

3.3The completed surface shall approximate the lines and grades shown or ordered. When ordered, stone placed over 1 ft.

outside or above such lines and grades shall be removed.

3.4Stone fill (Bridge) shall be placed within the limits shown on the plans.

Method of Measurement

4.1Stone fill will be measured by the cubic yard and in accordance with 109.01.

Basis of Payment

5.1The accepted quantity of stone fill of the class specified will be paid for at the Contract unit price per cubic yard complete

in place.

5.2Gravel blanket material specified or ordered will be paid for under Section 2 09.

5.3Geotextile specified or ordered will be paid for under Section 593.

New Hampshire Department of Transportation Standard Specifications – 2016

5.4The accepted quantity of excavation required for placing stone fill and for placing any underlying gravel blanket will be paid

for under the item of excavation being performed. Excavation herein refers only to excavation of original ground or to material ordered removed not shown on the plans.

5.5Free borrow will not be required to replace the accepted quantity of stone obtained from the excavation. However, when the

plans do not call for borrow, but the quantity of material removed from excavation for use under this item requires the Contractor to furnish borrow to complete the work, such borrow will be subsidiary. Pay items and units:

585.1Stone Fill, Class A Cubic Yard

585.2Stone Fill, Class B Cubic Yard

585.21Stone Fill, Class B (Bridge) Cubic Yard

585.3Stone Fill, Class C Cubic Yard

585.4Stone Fill, Class D Cubic Yard

New Hampshire Department of Transportation Standard Specifications – 2016

PIPE-ARCHES, AND ARCHES Description

This work shall consist of furnishing and installing steel structural plate pipes, pipe -arches, or arches, of the size and type

specified, at the location shown on the plans or ordered. 1.1.1 Structural plate pipe as mill fabricated shall be elliptical. Materials

Materials and design of plates and metal bearings shall be as specified on the plans or in the AASHTO “ LRFD Bridge Design

Specifications” unless otherwise provided hereinafter.

Plates and fasteners shall conform to AASHTO M 167.

2.2.1 Dimensions, including the thickness of plates, shall be as shown on the plans.

Elliptical requirements for pipe. Pipe under the item of structural plate pipe shall be fabricated elliptically so as to increase

the vertical diameter 5 percent and decrease the horizontal diameter 5 percent. These dimensions shall be subject to manufacturing tolerances.

2.4Backfill shall conform to 209.2.1.2.

Construction Requirements

General.

3.1.1 The Contractor shall provide for the temporary diversion of water in order to permit the installation of the structure in a reasonably dry trench unless otherwise permitted. 3.1.2 Fabrication, assembly, and installation of structural plate structures shall be as specif ied in the AASHTO “ LRFD Bridge Construction Specifications” unless otherwise specified hereinafter. 3.1.3 Where soft or other unsuitable material is encountered, all of such unsuitable material shall be removed for the depth shown or ordered. See Figure 1-a. 3.1.4 Where bedrock or other incompressible material is encountered, it shall be removed to a minimum of 1 ft. below the flow line. See Figure 1-b. 3.1.5 Granular backfill or other approved material shall be used to backfill the spaces left by the excavation of material removed in accordance with 3.1.3 and 3.1.4. The material shall be uniformly compacted by the use of lightweight construction equipment.

Bedding of Pipe and Pipe-Arches.

3.2.1 The structure shall be placed at the designated locatio n on a prepared foundation of granular backfill so that the flow line of the structure will conform to the required grade. Pipe or pipe -arch structures shall be set on a uniformly compacted bed of fine granular material 1 ft. deep, or as ordered, below th e bottom of the structure. The bed shall extend under the structure and at least 1 ft. beyond each side of the span. See Figure 1-c. 3.2.2 The granular backfill shall be carefully shaped by means of a template to fit the lower exterior of the structure, forming a trench equal in depth to at least 10 percent of the height in the case of a pipe- arch and 15 percent of the height in the case of a pipe. Care shall be taken to maintain the height of the edges of the bedding. Reasonable latitude will be permitted to allow for the field bolting of both circumferential and longitudinal seams of plates that are in the area of the shaped trench. When the top of the granular backfill is above the natural ground, fill for lateral support shall be constructed on each side of the granular backfill for a distance of approximately 2 times the span of the pipe or pipe-arch. See Figure l-c.