INSTALL 2018 - Laserfiche WebLink

Home Browse Search

APPENDIX D Split Backfill Guidelines I.GENERAL 2.5.Secondary backfill must be compacted to achieve a minimum I.I.Use se led rounded or crushed stones for primary backfiIImate rial of 85 percent stand a rd proctor density. as specified in the Installation Manual in effedattime of installation, 2.5.1.Do not use rammer-type compactors over the top of the tank. and Appendix C,Primary Backfill Requirements. 2.5.2.Someta nk owners may require sample testing and written 2.SPLIT BACKFILL INSTALLATION reports to verifythe compaction of the backfill. 2.1.Use the primary backfill material vertically up to at least75 percent 2.6.Material must be installed in 12-inch[30-cm]to 24-inch[60-cm] of the tank diameter.See Figure D-1. lifts compatible with the compaction equipment used. 2.2.Follow the instructions in section 5 of the Installation Manual on 2.7.In some conditions,frost heave may be encountered when using the placement of this backfill material. secondary backfill.Therefore,consider any frost-related problems that 2.3.Install a layer of geotextile fabric overthe entire surface of the may occur. primary backfill material.See section 1 for more information about 2.8.Specifications for secondary backfill material and compaction geotextile filterfabric. above the geotextile fabric layer may be determined by the requirements 2.3.I.All joints inthe geotextile fabric should beoverlapped of the piping,surface slab or roadway. a minimum of 12 inches[30 cm]. 2.9.Refer to applicable codes or standards for base course 2.3.2.Geotextile fabric must overlap onto the tank and excavation and sub-base course material and compaction requirements. surface a minimum of 12 inches[30 cm]. 2.10.The following are examples of acceptable secondary 2.3.3.Installations with unstable soil may require that the fabric line backfill material: the entire excavation.See section 1 forspecific information about using &clean native backfill geotextile orfabric in unstable in-situ(native)soil conditions. coarse sand or gravel 2.4.Clean native backfill may be used as secondary backfill material 2.11.100%of all backfill material must pass through a 1-inch sieve. above the geotextile fabric to subgrade. 2.4.1.Secondary backfill material must be clean,free-flowing, and free of large rocks,roots,organic materials,debris,ice and snow.Backfill material shall not be frozen or contain lumps of frozen material at any time during installation. �Grade or5ubgrade _ I _ Secondary Backfill Material - —IIIII =IIIII i' IIIM Filter Fabric With A IIII = —IIIII Filter Fabric With A Minimum of 12"Overlaps =IIIII — Minimum of 12"Overlaps IIIII —_ Primary Backfill Material = IIIII III=II I=I —IIIII III = 75%of Tank IIIII—III III—IIIII Diameter —IIII IIIII= IIIII—IIII 12"Bedding IIIII=IIIII=IIIII IIIII=IIIII=III =IIIII=IIIII=IIIII PER I = =I 44 APPENDIX D