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Attachment B-Change Order No.2 Silver Point Park&Central Park Storm Water Improvement Project City of St.Anthony WSB Project No. 1065.30 Parking Lot Subgrade Within the parking lot, Rozelle Drive and the adjacent basketball courts, the soft and/or organic subgrade must be subcut approximately two feet(2'),geotextile fabric placed and backfilled with well-graded granular soil having less than 10%fines (passing the U.S. No. 200 sieve). These granular materials should be placed and nominally compacted in one lift. The surface should achieve a density in the range of 93 percent to 95 percent of the Standard Proctor maximum dry density (ASTM D-698). The pavement aggregate base of eight inches (8") of Class 5 aggregate must be placed and compacted as per the specifications. The surface of the sand subgrade should be test rolled priorto placement of the Class 5 aggregate base. Deflections(weaving)on the order of one inch(1")maybe acceptable. However, rutting of the subgrade soils would not be acceptable as indicative of shear displacement in the underlying base and likely intrusion into the sand subgrade(sub- Vbase). Within this parking lot,a storm sewer will pass several feet below the pavement surface. The backfill material above the pipe zone(the pipe should be properly bedded in granular soil)should match the consistency,type and relative density of the soils excavated within this zone. That is, if stiff mineral soils were excavated, backfill material to subgrade elevation should be mineral soils, properly densified to achieve a similar but slightly stiffer matrix. If the soils are partly organic in nature,similar soils should be placed and nominally densified to achieve a similar consistency to the surrounding subgrade soils. An alternative to this would be to transition from the pipe trench zone to the natural subgrade at a slope of four horizontal to one vertical (4H:1 V)so that there will be no trench demarcation at the subgrade surface. Where fill materials in utility trenches are unable to achieve the specified density as required in these specifications,altemative compaction requirements may be accepted (zero air void compaction criteria), provided an additional warranty period is agreed to and additional crown is placed within roadways above the inferior trench backfill to allow for long-term settlement of the backfill material. Bituminous Pathways The eight-foot (8') bituminous pathway within the park will have a typical section consisting of a width of the Class 5 aggregate base(100%crushed limestone)which extends six inches(6")on either side of the wearing course. The Class 5 aggregate base material width would be approximately nine feet(9')with a depth of twelve inches(12").