306 ALDER ST 2018-01-02 MF Import

May 7, 2001 � Rockery—Pete Peters Residence L&A Job No. ]058 Page 4 The '�ll soils underlying the site is of lrigh sheaz stren,th and excellent resistance against soil movement. lt is our opinion that the cut made in the very dense till soils should remain stable on a long-term basis when Lned with rockery that is prope�ly designed and constructed. The fill embankment to be lined by rockery should be constructe�� over the underlying, very dense, fresh till aPer the surScial topsoil and unsuitable soils in the root zone aze stripped off. If the fill is to be built over a slopino ground, the slope should be benched to a series of steps about 4 to 6 feet wide nrior to placing the 811. ROCKERY DESIGN AND CONSTRUCTION Our designs of the rockery wall to be constructed on your property aze shown on Plates 1 and 2 attached hereto, for liuing cut bank and fill embankment, respectively. The rock material for rockery consuuction should be hazd, sound, durable and free of cracks, �s�.:res and other defects. The facial stones should be as neazly rectangulaz as possibie and stacked tign±ly against one I another to m;,,�,T,ize the voids between the stones. Excessive opendngs behveen the facial stones should be chinked with smaller rock from behind. The facial stones of the rockery should be sloped back at a batter no steeper than 6V:1H. The base course facial stones should be set an firm, undisturbed, native soils with its bottom set at least 12 inches below the finish grade in front of the rockery. The bearing soils should have an allovs�able beazing pressure of at least 3,000 psf. The facial stones of each course should be staggered and supported on two stones of the course below. The fill embankment should be coastructed of structural fill consisting of clean, &ee-draining, granular soil containing no more than 5% by weight finer than the No. 200 sieve based on tue fraction of the material passing No. 4 sieve, and shouid have individual particles not greater than four inches. Structural fill should be placed in no more than 10-inch Gfts in its loose state, wit6 each ;ift compacted to at least 95% of the maximum dry density determined by ASTM D1557-78 (Modified Proctor Method). Suuctural fill should have a moistur� content wiUrin 2% of 'sts optimum moisture content at the time of placement. The optimum moisture content is the water LIU &ASSOCIATES,INC. O