DIVISION 1 - GENERAL REQUIREMENTS - IDEAS-EC

C. Make excavation large enough to permit installation of utility connections and removal of forms.D. Excavations shall remain open only as long as necessary to complete the associated work. TheContractor shall notify the Contracting Officer at least 24 hours before beginning any excavationand shall inform the Contracting Officer of the intended time the excavation will remain open.E. Protect excavation from moisture infiltration, ponding of water, frost, erosion, and constructionactivities that could soften the base of the excavation.F. If the Contracting Officer approves excavation below the design elevation because of unsuitablefoundation material, an equitable adjustment will be made. If unauthorized overexcavationoccurs, repair the area by backfilling with approved material and compacting to 95 percent of themaximum density at no additional expense to the Government. No adjustments will be made ifunsuitable material is the result of improper protection from moisture infiltration or constructionactivities.G. Do not place backfill against retaining walls or foundations until entire structure has beencompleted and concrete has reached required 28 day strength.H. Place all backfill in 6-inch horizontal lifts. Compact all 6-inch lifts to 95 percent of the maximumdensity. Place an entire lift prior to placing the lift above it.I. Contractor shall carefully excavate, handle and stockpile excavated material so as to maximizeuseable material and minimize contamination of suitable material. Any material that becomesunusable due to contamination with unsuitable materials or because of improper handling shall bereplaced by the Contractor at no additional expense to the Government.3 .2 EXCAVATION MATERIALSA. Use suitable material removed from excavation before importing backfill.3 .3 TANK AND RETAINING WALL FOUNDATIONSA. Bring Subgrade to required elevation using select fill. Fill shall be compacted in 6" layers to 95%of the maximum density. If the subgrade is unstable at grade established, remove unsuitablematerial and replace with select fill in 6-inch layers.B. Place 6" layer of aggregate base and compact to 95% maximum density.3 .4 DISPOSALA. Dispose of surplus and unsuitable material as specified in Section 01570.PART 4 MEASUREMENT AND PAYMENT4 .1 Payment will be included in the bid item to which this work relates.END OF SECTION02318-2STRUCTURE EXCAVATION AND BACKFILL