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HomeMy WebLinkAbout312 W 3rd St - Land Use 1 1 SLOPE STABILITY MONITORING 1 F" 1 44 a i t'''''. r..", ir i ,e es r 41P Ilr A, liop..., E Vic. Goo e 1 1:. a r� 1 Prepared For Thang Ly Qing Zhang July, 2012 For the Property Described As I TPN: 063000 007150 312 West Third Street Port Angeles, WA 98362 1 o Prepared by ti�'� 1 Trent T. Adams, EIT A. \„\c,1 NTI ENGINEERING SURVEYING 717 S. Peabody Street 1 Port Angeles, Washington 98362 Phone: 452 -8491 Fax: 360-452-8498 I Web Site www.nti4u.com 1 w E -mail info @nti4u.com 1 1 1 Purpose 1 Northwestern Territories, Inc. Engineering and Surveying (NTI) was retained to conduct the 2012 slope stability monitoring at the residence of Thang Ly Qing Zhang, TPN I 063000000072150000, at 312 West 3rd Street, Port Angeles, WA 98362. NTI completed an engineering site investigation of the property in September 2011 to determine a suitable inspection monitoring plan of the slope, yard, home, and garage conditions over the 1 next several years. As part of this project, a surveyed slope stability monitoring system was implemented in December 2011, on behalf of Thang Ly Qing Zhang. I The primary purpose of the periodic slope stability monitoring is to examine ground movement of the property, noting any areas where soil erosion has occurred. The work determines any changes in elevation of the soil based on the initial surveying of the site done December 2011. I Any potential areas of erosion are checked during the next inspection and evaluated for changes in elevation. I Background Information The monitoring requirements were outlined in a letter by NTI in February 2012. 3 fixed markers 1 and 4 monitoring points have been mounted by NTI Surveyors in strategic locations on the property. It is understood that the frequency of annual monitoring shall be every 6 months for the first two I years and once a year for an additional three years. At the end of the five year monitoring program, the need for additional inspection and monitoring shall be inspected. 1 Site Description The property is a single family residence with a main floor of 1323 square feet, a basement area I of 297 square feet (per the assessor records) and includes an addition to the original house footprint located above the garage on the west side of the lot. The lot is nearly level, sloping gently at 3% or less in the rear yard area behind the house. Limited undeveloped (yard) space I exists in the front and back. The front and side yard to the east are grass covered with some landscaping near the foundation, and narrow concrete walkways around the house on the property, in addition to the city sidewalk at the front of the house. The back yard space includes a deck, level with the first floor, extending across the rear of the original house. A small portion I of the back yard is currently in use as a vegetable garden. The lot is bounded to the west and south by steep slopes, which extend down to Valley Street and Valley Creek. I Slopes to the west and south extending below the subject property are typically 30% or more, steepening to 60% or more just below the parcel boundary. Slopes are well vegetated with various creeping groundcover, both native and non native, some shrubs, and some large trees. I Trees are generally vertical, lacking the curvature or jackstrawed conditions that typify slopes in motion. Scattered household debris was found on the slope. I Soils mapped on the slope are of the Neiiton series, and are typically comprised of very gravelly loamy sand on 30 70 slopes, characteristically well drained. Soil condition varies from loose to moderately dense near the surface and well confined by existing vegetation. Soils on the I parcel are of the Clallam Hoypus series, typically well to excessively drained, and generally 1 1 1 moderately dense at the site. Subsurface geologic unit is mapped as Vashon drift, undivided, 1 typically comprised of mixtures of sand and gravel, till, and some lacustrine silts. Slope Stability Monitoring 1 Monitoring of the site control points and markers was performed by NTI Surveyors on June 6, 2012. Measurements of changes in elevation were performed by Trent Adams, a licensed EIT of 1 NTI from the survey data. Measurements determined from survey data are recorded in Table 1 of the Appendix. 1 Mapping of the monitoring points is also shown in the Appendix. Conclusions The slope stability monitoring program is functioning as designed. No areas of erosion were 9 observed from the survey data. Changes in elevation were minor at less than 3/100's of a foot. All monitoring points will be inspected and surveyed again in December 2012. 1 Sincerely, NTI Engineering Land Surveying 1 Trent T. Adams, EIT 1 1 1 1 1 1 1 i APPENDIX I nrInKKKK o H O O O m D 0000 v, co I Z Z Z Z n r O 0 0 0 0 0 0 I v -1 -H -I A w N I- N IL Q1 I n w N O N p Z D I u, u, U, Ln Ln U1 Ln D O O O O O O O O h- O O O N o 00 O J=. V LO M U'I V, m r r 0 1 I- up I- o o LID T m o u, o V LO H v, O lD N A N lD D 4=.r..)-p. V A 00 N W I K K K K 0 0 0 0 0 v z z z z 3 0 0 0 0 0 I 7 x z 2222 z z Gl G) Gl -a -o -o -o -H -H cn Z -P w N I- 01 +n N 1 no m w m o D Ui U, v, U1 -p 0 -i 0 O N 0 Z D z -1 0 x* D I m D 0 0 lD 0 0 LO 00 T V F� V H o w A U.) Ul Ln 1 C T T To m D O O O m D Z I 1-< D O Z 1 1 1 1 1 IIIIII IM 1 11 II II IM MI 1 MI II IN III III MI MI IN MI III NEI 1 1 1 11 II a q N O 0 m r C N C Z d D z T y, r.:+ -.3N z —i D w oo z ,,,,i, -N4111111 r Z .4( ,..i. 4.. .x- 1., 44,,,, ‘.5' V.4. �.0 1 If NTI EN m NORTHWESTERN TERRITORIES, INC. 2012 PRELIMI MO NITORING PLAN ENGINEERING SURVEYING y SYY. REVISION DATE BY CHECKED 3 12 W THIRD STREET, PA, WA, 98362 1 a r SCALE: 1 2 I DATE: THANG L Y Q ING ZHANG 717 SOUTH PEAR nd Survey ODY STREET, PORT ANGELES, WA 98362 47A DESIGNED Br: Tr„, Geologis ���r DRAWN B Y iTA Construction I ns p ection Mate rials Te Yp�q, M' CHECK JCW N 111,1: SHE ENDR. CONST. 360) 452 -8491 FAX (360) 452 -8498 SHEET 7 Oi 2 1.111 Mil 11.11 I ME ME MI Mill .M MI Mil r R =o N ca V 0 m WW N co r Y •i /v 0 1 C m 0 =Dz m 0 D 0 w .a r r N Z i a, .,A t r ",f fy 4.*,' (III 4 \'1Iiiii�luu 4 C, Z ENO 4 5 17 NA J 1 0A r w p p 3' W 1 yy W 0 NORTHWESTERN TERRITORIES, INC. 2012 ...makes SLOPE STABILITY MONITORING PLAN NTI ENGINEERING SURVEYING as y°a SYY. REVISION DATE BV CHECKED 312 W. THIRD STREET PA, WA, 98362 I Yis SCALE: 1 20 I DATE: THANG LY QING ZHANG t 717 SOUTH PEAeBODY STREET, PORT ANGELES WA 98382 DESIGNED BY: rTA Engineers Land Surveyors Geologists t'�. ��i DRAWN BY: TTA Y F n CHECKED: JCW Construction Inspection Materials Testing N REVIEW: ENGR. CONST. N7'/ (360) 452 -8491 FAX (360) 452 -8498 SHEET 1 OF 2