244 HEATHER RD 2016-01-01 MF Import

U% '29/1997 .4:15 2063655573 GTTEtJ E�dGINEEkING Fa,E C+3 . Mark T. Otten, P.E. Bn�incering Consultant - , The report also did not point out that the west slope is coverea w�in veriica�,�un��«d�=� uees, I observed a few tr�es with curved trunks, which is an indication soil movement downslope. On the other hand,the number of n�ahue Vees with straight trunks indicatcs that the overall slope haz been stable for scvcral decades. There aze two lazge evergreen uees along the �vest side�if the yard,which appear to be verticel and unaffected by the recent soil movement. Slope Stabilization Objectives The prefeaed slope stabilization methods depends on your objectives. Listed below are four poasible objectives: . Protect the house from stnutural damage, • Protect the house from cosmetic damage (e.g. plaster�r tile cracking), • protect the yard from further sliding, • Stabilize the west and south slopes from future sliding. Slopc StAbiliz�don Metbods - Slopes can be atabilized by several methods, which I divide into the following categories: l, Make the slope►ess steep, 2. Inctease the strength of the soil, 3, Improve surface and groondwater drainage, 4. Construct earth retaining wells. Making the slope less steep would require removal of soil £rom the west yard area. Soil fill cau weigh 100 to 120 pounds per eubic foot, so that a une L-,�ak la�er of soil ov:r an area of 80 feec by 20£eet would weigh 80 to 100 tons. �emoving soil fro�.the top of a slope improve stahility by reducin�the£orces pushin�down on soil below. Given the site and soil conditions, increasing the soil strength does not appeaz to be a feasible alternative. Improving the drainage will help,but is not expected to be sufficient for loag-term stability. It dces appear feasible to lower the elevation of the west yard. There are several types of earth retaining walls. One co�runon class of walls is a"gravity wall" that uses the weight of ttte wall material and sliding friction at the base of the wall to resist tl�e lateral force of the soil and buildins upslope of the wall.Types o£gravity walls include(a)lar�e conerete blocks, (b) ra:keries (c)reinforeed earth(d)crib walls, or{e)reinforced concrete walls with wide base footings. Rackories aze typically one row of larg�rock stacked on top of each other and are generslly the lowest coet cption,but provide th� least support. Large cuncrete blocks(ecology blocks) are cummonly used for support of soil heights of 6 to R feet. One type of rock wail, called gabions, is composed of wire baskets filled with rock. 2 ��zar9� � 07'SLTk.�OC