5627 1ST AVE SE 2016-01-01 MF Import

. � _ Geotechnical Consuitation Services Page 2 - 93-1397 Hannabrook Rock Wall - Lots 39 through 45 July 26, 1993 of a protective rock wall, is considered appropriate to provide sufficient space to construct a residence and include both a front and rear yard area. In order to achieve this distance it appears that some excavation back into the eastern soil slope will be required. The specific amount of excavation into this slope is expected to vary lot to lot. The soils exposed along the potentiai alignment of the protective wall excavation consist predominantly of a dense fine to coarse sand with a little rounded fine to coarse gravel. There are also varying amounts of sik intermixed with these sand soils. Given the competent in-place condition of these materials, it is our protessional opinion that it is appropriate to protect the exposed soil surface with a rock wall. On the basis of our site measuremeMs it appears that the wall should be expected to extend for a distance of approximately five hundred and sixty (560) feet from north to south. Over this distance the wall is expected to vary beh�veen about two feet and eleven (11) feet in maximum height. The wall is to taper up from the north end to the full wall height and then badc down towards the south end. The estimated average wall height is on the order of about six feet. The maximum estimated wall height, eleven (11) feet, includes a minimum of one foot of burial into the excavated wall keyway. We understand from the rockery contrador that the walt is to be built essentially as a single unit from one end to the other to create a contiguous structural element. The area above the wali is cuRently sioped up to the adjacent existing residential properties. The slope is estimated to be between approximately 34 degrees, or about 1.5:1 (horizontalvertical) and 28 degrees, or about H: V. On completion of construction, we understand that this slope is to be re-graded to an inclination of approximately 1.5H:1 V, or flatter. The finished surfacs is to be re-vegetated to help prevent surficial erosion. In the event that there is a change in the proposed site treatment we should be immediately informed of the changes. This will allow us to evaluate the changes and determine what impacts, if any, the changes might have on the recommendations cont:�ined in this report. It will also allow us to provide any necessary ��udifications to our recommendations before wall construction gets underway. Scooe of Services Our scope of services, developed during our discussions with Mr. Tim S:arns (your rockery contractor) and Mr. Bill Schauble your superintendent, includes the following: ■ An initial site visit to examine the existing site conditions and to assess the nature and competency of the exposed site soils, -