209GRANULAR BACKFILL

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1This work shall consist of furnishing and placing porous granular material at the locations shown on the plans or ordered.

Materials

2.1The material shall consist of stones, rock fragments, and fine hard durable particles resulting from the natural disintegration

of rock. The material shall be free from harmful amounts of organic matter. The wear shall not exceed 60 percent. No more than 12 percent of the mat erial passing the No. 4 sieve shall pass the No. 200 sieve, and the material shall conform to the following gradations: 2.1.1 Granular backfill (sand) shall consist primarily of particles with 100 percent passing the 3” sieve and 70 to 100 percent passing the No. 4 sieve. 2.1.2 Granular backfill (gravel) shall consist of a mixture of stones or rock fragments and particles with 95 to 100 percent passing the 3” sieve and 25 to 70 percent passing the No. 4 sieve. 2.1.3 Granular Backfill (Bridge). When this item is specified the material shall meet the gradation requirements of Item 304.2. 2.1.4 Granular Backfill. When this item is specified, the gradation shall conform to 2.1.1 or 2.1.2.

2.2Concrete class F, flowable fill may be requested in writing as a substitute for granular backfill. Approval shall be in

consideration of, but not limited to, differential frost heaving due to dissimilar materials, unit weight, structural requirements, lack of permeability, and damming resulting from water flow cut off. Construction Requirements

3.1Granular backfill of the specified or ordered gradation shall be placed in layers at the locations shown or ordered. Backfil l

shall be placed in the manner detailed in the appropriate section in which the backfill is specified. The backfill layers shall not exceed 8” of compacted depth unless otherwise directed. Density shall meet the requirements of 203.3.8. Method of Measurement

4.1Granular backfill will be measured by the cubic yard in accordance with 109.01 . When granular backfill is specified as

included in another item, no separate measurement will be made for the backfill furnished in connection with that item.

4.2Backfill of over-excavated areas beyond or below the lines and grades shown or ordered will not be measured for payment.

4.3For pipe having an inside diameter of less than 48” no deduction will be made from granular backfill of the volume occupied

by the pipe constructed under 603 when granular backfill is ordered as bedding material.

4.4Granular backfill (bridge) will not be measured, but shall be the cubic yard final pay quantity in accordance with 109.11 for

compacted material required within the limits shown on the plans. Basis of Payment

5.1The accepted quantity of granular backfill, of the type specified, will be paid for at the Contract unit price per cubic yard

complete in place.

5.2Granular backfill (bridge) is a final pay quantity item and will be paid for at the Contract unit price per cubic yard complete

in place in accordance with 109.11.

5.3Concrete class F, flowable fill substituted for granular backfill will be paid for at the Contract unit price for granular backfill

of the type specified. Pay items and units:

209.1Granular Backfill Cubic Yard

209.20X Granular Backfill (Bridge) (F) Cubic Yard

209.3Granular Backfill (Sand) Cubic Yard

209.4Granular Backfill (Gravel) Cubic Yard

New Hampshire Department of Transportation Standard Specifications – 2016

Description

This work shall consist of monitoring construction related vibrations and setting vibration limits to avoid damaging existing

nearby structures, properties and utilities located on or near this project. 1.1.1 Sources of construction related vibrations which are covered by this specification include compaction equipment (sections 203, 209, 304, 508), cofferdam construction (section 503), sheet piling (section 506) and bearing piles (section 510) or other construction activities as identified. The provisions of section 203.3 shall still apply to vibrations caused by blasting operations.

1.2The work under this specification includes providing the services of a qualified Vi bration Consultant.

1.2.1 As part of this work, the Vibration Consultant shall submit vibration documentation as described in 211.3.7. Construction Requirements

Vibration Consultant Qualifications. The Vibration Consultant shall meet all the applicable qualification requirements of

203.3.3.1 and203.3.3.2. The same Vibration Consultant shall be used on all monitoring activities throughout the project.

3.2Vibration Monitoring Plan. Prior to initiating a particular activity which requires vibration monitoring, the Contractor shall

submit a Vibration Monitoring Plan prepared by the Vibration Consultant. The plan shall be submitted a minimum of 10 working days prior to beginning the particular construction activity. The construction activity shall not begin until the plan has b een approved, except as allowed under 3.2.1. 3.2.1 Prior to the production phase of the particular cons truction activity, the Contractor will be permitted to conduct a test program to establish the allowable vibration limits, subject to approval. The production phase shall not begin until the res ults of the test program have been approved. 3.2.2 The plan shall include the following:

for a test program in accordance with 3.2.1, if the vibration limits cannot be predetermined. Justification shall be provided for all recommendations.

a pre and post construction condition survey in accordance with 3.4. This recommendation shall pay particular attention to historic structures, structures in poor condition, structures supported by vibration sensitive materials which could cause settlement or loss of support, and structures which contain sensitive equipment or processes. The Monitoring Plan shall also include methods for measuring deformation or settlement of selected structures, if deemed necessary by the Vibration Consultant or Engineer.

exceeding vibration limits that are necessary to protect adjacent facilities. 3.2.3 As part of the review of the Monitoring Plan, the Engineer may require modifications to the submittal to include, but not limited to, surveying and monitoring of additional structures, the number of monitoring sites and the distances for monitoring. There may be a need for simultaneous setups with multiple monitoring devices.

3.3Vibration Monitoring Instrumentation. All vibration monitoring equipment shall meet the requirements of 203.3.3.7.

3.4Pre and post construction condition surveys. The Contractor shall conduct a pre- construction condition survey on all

structures, including swimming pools and mobile homes, within 150 feet of the anticipated sources of construction related vibrations. A pre-construction survey shall also be conducted on structures that may be affected by construction related vibrations beyond the 150 foot distance as directed by the Engineer or as contained in the approved Vibration Monitoring Plan. The pre - construction surveys shall not be initiated until the Vibration Monitoring Plan has been approved. Upon completion of all construction operations that are a source of construction related vibrations, the Contractor shall conduct a post -construction condition survey of any structure for which a complaint of damage has been received or a damage claim has been filed. Notification of the post-construction survey shall be given to all interested parties, so they may be present during the survey. A copy of the pre-construction condition surveys shall be provided to the Engineer prior to the start of work. A copy of any post -construction condition survey conducted shall be provided to the Engineer upon its completion.

3.5Coordination Meeting. A coordination meeting arr anged by the Contractor shall be held prior to initiating the particular

construction activity and the associated vibration monitoring. The coordination meeting shall not take place until the Contractor has submitted and received approval of the Vibration Monitoring Plan. The purpose of the meeting shall be to review all aspects