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1997 Analysis of Landslide Material Loss, Portuguese Bend Shore Protection Feasibility Study
F r1TY O CHO PALOS VERDES ' . ..!„ aY CORPS OF GI MEERS PORTUGUESE BEND SHORE PRa ECTIOH FEASIBILITY STUDY in SLIDE 4 jE RIAL Loss its o°' CHA► ` i1: i :16) . _ , , 371 Van Torran:.,.: LANDSLIDE MATERIAL LOSS BACKGROUND The Portuguese Bend Landslide has moved continuously over the past forty years. Vonder Linden (1972), attributes this continued movement partly to a notable rise in the ground water table between 1957 and 1968 and the continued erosion of the toe by wave action. The rate of movement varies considerably in response to variation in ground water levels (Vonder Linden, 1972). In 1978, above average rainfall caused a large increase in the rate of movement in the Portuguese Bend Landslide. The high rates of movement continued until 1986 when the Rancho Palos Verdes Redevelopment Agency performed remedial grading. For example, one survey mon- ument, R-1, (see Figure 1) which is located in the east central part of the landslide, moved 382 feet hor- La. . oic _ - izontally in the ten Y '.4:$,, 4 ' .` °"' year period from 'y . _. October 1976 to Oc- s - tip, Orl-- : tober 1986 whereas - , it had moved 237 - .; .. i feet during the , ,� - ,,` ' twenty year period 4,'�, from October 1956 N. :. a '` to October 1976 , - (Ehlig 1991). Near i ' the coast, the corre- • ;„ . lation of offset fea- = - y 3 '' c�* . tures indicates dis- . _y _` -. + , - placements of more _,„; • ' :.. than 800 feet since "r• •F y;- . '; �, K J ,� the start of landslid- •r • `. ing. `"`. .- - C 4 A sediment plume - ~E� r tit has been visible in :'. ' the ocean since the _„; start of movement tik - in 1956 . Landslide ` " ,� sediments have ' ' }. '" .., been identified 2.5 - �� -�, nautical miles to the `' . '1 , south of the land- Sediment Plume from the 4-...•,.,,,, slide and 1.5 nauti- Portuguese Bend Landslide. cal miles off-shore ' -1- G \ \�500 4krigg41B�w 4, ' �\ aa� °a. ��'O 'G -\ NI —N4A20.000 nr__ /,.. ,ke N4,020,000 it \3 -----\ 0., i---- S b .* f-/--r , c---- \,_ /3 ,s2 36 c'\ V ,' c-"2 l OCT 1956 to 0 197 1 eet i 28 -.,__/A eE pe�R ten- ao Portuguese con 97 t CT 1986 +*I tea ' —� et 240-_________ 1 24� I to. r k744\.�,�'/ ".-22. -cyF�P,pr ao !k NIV 1 A 4,018Aa. PALOS VERDES DRIVE N4.01 B4Oee C4I 1s0�s O '^ ��z00 0 tib ` 100�— �1bC \�/ i b0.� bo l'Sq�� PACfFic OCEAN ,.>„ Oil Figure 1 \ 0 300 600 FEET \ (Base Map,1995) \ (Stevens, 1990). It is estimated that sediment from the Portuguese Bend Landslide affects the marine environment in an area of approximately 771 hectares in size (Stevens, 1990). The photograph on the previous page shows the sediment plume from the Portuguese Bend Landslide in 1980. ANALYSIS In determining the amount of landslide material that has been lost, cross-sections were drawn using topographic maps of the area from 1955, 1976, 1984, 1987, 1988 and 1995. By comparing the area between cross-sections on the first map, dated August 1955 (prior to the start of landsliding), and cross sections taken at the same location on subsequent topographic maps, a difference of the upslope removal and the downslope fill can be computed. However, in this situation where the entire landslide mass is translating downslope in a non-uniform manner, the typical approach to calculating the difference between removals and fills does not explain how parts of a mass can translate up to 800 feet without that part of the entire mass being dispersed into the ocean. Therefore, the difference in density of the material in slide mass before landsliding began, and in 1995, must be taken into account after the typical difference between removals and fills are calculated. In order to calculate the difference between the removals and fills created by the land- slide, a total of eight (8) cross-sections were computed between the easterly edge of the landslide and Inspiration Point for each topographic map. The location of the cross-sec- tions are shown on Figure 2. The various cross-sections are included in Attachment A. Adequate maps are not available to determine the amount of land movement in the area between Inspiration Point and Portuguese Point. Therefore we did not take cross-sec- tions in this area. Volume of displaced earth was determined by using the average end area method. Volume calculations were broken down into three portions. Portion 1, the removal, included the material between the location of the bluff in 1955 or limit of landslide and the top of the landslide. Portion 2 included the material between the 1955 shoreline and the location of the bluff in 1955 which is part of the fill area. Portion 3 included the material between the 1955 shoreline and the shoreline in later years and represents the part that the landslide has encroached into the ocean. Figure 3 shows the general loca- tion of the three portions used in our calculations. Based on this volume analysis, we estimate that the amount of material that has entered the ocean due to landsliding is approximately 3,584,000 cubic yards. However, as stated earlier, this does not account for the total amount of material dis- persed into the ocean. Because of the loss of density of the moving material in the slide mass, another significant amount of material has been moved into the ocean. Once the -2- N.,,____....:—.‘„______ aa� 3 `�-�, c \u/ cgs '}1 �� 61'— �V �1. 00111No ��❑ �FIIIIIINII. OINNsyq�e` w7 \\ QQ a ki; Ian styf�g1 % < AY,pD il i Sill I I —N,020,00 \ N4,D20,DDD� 738 G li r .cr 1,0„, ) AIN. .• . • \K\k y \„,),%. - --r Qaa ...4, � cols f .� OFF �1 2B0 / OIIUgO■6■Can • 260. 1111 '' 14 •. I 00 i In u -22. I / V. iac.,..,:_:, I 8 \ /N4D)8JD. 1 PAL)SVERDESOR/VE' &O1&flD \�180 i \ 111( ie. `�elle Al .r: a\ ,_., 18 C ,,,,:./)/-\4 ,(-1 ; 4.74% ji.j. "7 .4"1 ' �T o ; aQ 2 • c!> N WO i "kik of 3 `��Y ♦ 1 PACIFIC 'OCEAN A 1 �,( �9i,�,� �F :. 5 G 6 7 � � Figure 2 0 300 600 FEET ® ^X (Base Map,1995) V CROSS-SECTION 4 P•R ION 2 tn PORTION 1 b 1:6 � a C` - o H 1955 Cross-Section 1995 Cross-Section ______ 1995 Cross-Section 1955 Cross-Section Figure 3 mass began moving downslope, a number of factors have affected the speed of the landslide mass. These factors include: 1) the height of ground water above the slide plane, 2) the depth of the slide mass, 3) the slope of the slide plane, 4) the friction of the material at the slide plane, 5) the amount of support, particularly at the bluff and 6) the rate at which the ocean removes material along the shoreline. These factors vary throughout the landslide. Survey data indicates that the most rapid movement has occurred within the oceanward part of the landslide south of Palos Verdes Drive South. Because the downslope portion of the landslide has a higher rate of movement than other sections of the landslide, grabens and voids are created within the landslide mass causing a significant reduction in the density of the original slide mass. For the pur- poses of this report, we have assumed that the loss in density is 10%. This assumption is based on our experience in mass earthwork construction where materials such as soils and rock that are loosened, typically show a 10%-15% decrease in density. The translation of the material occurs at a much faster rate in the coastal zone (Palos Verdes Drive South to the ocean) than in the inland areas. Therefore, pull aparts, grabens, and fissures are commonplace in the areas moving. Thus, the faster moving areas separate from the slower moving areas creating these void spaces and less dense material. From our cross-sections and calculations,we estimate the mass of the original landslide to be 22,480,000 cubic yards. Assuming a loss of 10% in density, the additional dis- persement of material into the ocean is 2,250,000 cubic yards. This brings the total amount of material loss due to landsliding to 5,834,000 cubic yards since the landslide began moving in 1956. Figures 4 and 5 on the following page show the cumulative amount of material loss and the average yearly loss for various periods between 1956 and 1995. As shown in Figure 5, the average yearly loss of material was 85, 633 cubic yards for the period from 1955 through 1976 and 207,795 cubic yards for the period from 1987 through 1995. CONCLUSION Two factors must be considered in determining the amount of landslide material loss; 1) the actual amount of earth that has moved into the ocean which can be verified using photographs and topographic maps, and 2)the estimated loss of density that has occurred as a result of land movement. Our calculations using verifiable information indicate that approximately 3, 589,000 cubic yards of earth entered into the ocean as a result of landsliding. In addition,based on our experience, we have estimated that the landslide mass has experienced a minimum 10%reduction in density as a result of land movement. This translates into an additional 2,250,000 cubic yards of earth that has been dispersed in the ocean. Therefore, the total landslide material loss is estimated to be 5,834,000 cubic yards. -3- CUMMULATIVE LANDSLIDE MATERIAL LOSS FIGURE 4 6,000,000 5,000,000 v 4,000,000 Year Cummlative Erosion (CY) a 3,000,000 1 1955 cc u' 1976 1,798,291 2,000,000 f 1980 3,606,855 1,000,000 1987 4,171,713 1988 4,853,645 1995 5,834,076 1955 1976 1980 1987 1988 1995 YEAR AVERAGE YEARLY LOSS FOR PERIOD 300,000 - Yearly Average(cy) FIGURE 5 1 250,000 1 1 U 200,000 , Total for Yearly Period Years Period Average CY Q 150,000 1 { ) (CY) I d 100,000 1955-1976 1,798,291 85,633 50,000 i 1976-1984 1,498,072 187,259 1984-1987 875,440 291,813 1955-1976 - 1987-1995 1,662,363 207,795 1976-1984 1 1984-1987 1987-1995 ATTACHMENT A CHANGE FROM 1955 YEAR 1976 1980 1984 1987 1988 1995 1 SUBSIDENCE 2,040,411 3,956,207 4,671,553 5,465,636 5,950,297 6,396,982 INFILL 1,994,248 2,060,989 2,819,481 2,742,001 2,630,278 2,250,303 BEYOND SHORELINE 497,963 538,364 805,798 801,922 716,374 562,603 X S ECTION BALANCE (451,799) 1,356,855 1,046,273 1,921,713 2,603,645 3,584,076 10% BULKING OF 22,480,000 C.Y. SLIDE 2,250,000 2,250,000 2,250,000 2,250,000 2,250,000 2,250,000 EROSION ' 1,798,201 3,606,855 3,296,273 4,171,713 4,853,645 5,834,076 1 A-1 1955 to 1976 EARTH MO i ci CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,050 8,000.00 9,700.63 450 161,677 6,500 11,401.25 12,730.35 600 282,897 7,100 14,059.45 18,086.33 300 200,959 7,400 22,113,20 22,265.80 300 247,398 7,700 22,418.40 25,102.83 300 278,920 8,000 27,787.25 27,625.00 300 306,944 8,300 27,462.75 27,606.33 300 306,737 8,600 27,749.90 16,896.33 300 187,737 8,900 6,042.75 3,021.38 1 600 67,142 9,500 0.00T l I 2,040,411 A-2 PORTION 2 INF[LL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 8,506.90 200 63,014 6,500 11,013.80 15,300.23 I 600 I 340,005 7,100 19,586.65 18,751.55 300 208,351 7,400 17,916.45 21,535.18 300 239,280 7,700 25,153.90 32,777.83 J 300 364,198 8,000 40,401.75 37,584.13 300 417,601 8,300 34,766.50 26,490.45 300 294,338 8,600 18,214.40 9,107.20 200 67,461 8,800 0.00 0.00 400 0 9,200 0.00 1,994,248 A-3 PORTION 3 [NFILL BETWEEN 1955 SHORE LINE & 1976 SHORE LINE South of 1955 i Shore Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 3,440.80 200 I 25,487 6,500 3,881.60 4,942.30 600 109,829 _ 7,100 574.00 ~� 6,451.88 300 71,688 7,400 6,900.75 7,978.75 300 r 88,653 7,700 9,056.75 9,240.88 300 102,676 8,000 9,425.00 6,343.75 300 70,486 8,300 3,262.50 2,226.25 300 24,736 8,600 1,190.00 595.00 200 4,407 8,800 0.00 0.00 400 0 9,200 0.00 497,963 A-4 1955 to 1980± EARTH MOVEMENT CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,050 7,000.00 13,143.13 450 219,052 6,500 19,286.25 16,106.63 600 357,925 7,100 12,927.00 27,174.50 300 301,939 7,400 41,422.00 36,282.00 300 403,133 7,700 31,142.00 40,506.00 300 450,067 8,000 49,870.00 1 68,511.94 300 761,244 8,300 87,153.88 68,843.74 300 764,930 8,600 50,533.60 37,782.05 300 419,801 8,900 25,030.50 12,515.25 600 278,117 9,500 0.00 f i 3,956,207 A-5 PORTION 2 INFILL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 9,926.00 200 1 73,526 6,500 13,852.00 8,446.50 600 187,700 7,100 3,041.00 11,128.50 300 123,650 7,400 19,216.00 23,271.50 300 258,572 7,700 27,327.00 38,941.50 300 432,683 8,000 50,556.00 48,355.19 300 537,280 8,300 46,154.38 33,4,90.07 300 371,112 8,600 20,645.75 10,322.88 200 76,466 8,800 0.00 0.00 400 1 0 9,200 0.00 2,060,989 A-6 PORTION 3 INFILL BETWEEN 1955 SHORE LINE & 1980 SHORE LINE South of 1955 Shore Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 3,668.00 200 27,170 6,500 4,336.00 2,255.50 600 50,122 7,100 175.00 7,153.75 300 79,486 7,400 14,132.50 10,431.00 300 115,900 7,700 6,729.50 9,740.00 300 108,222 8,000 12,750.50 9,611.38 300 106,793 8,300 6,472.25 4,030.63 300 44,785 8,600 1,589.00 794.50 200 5,885 8,800 0.00 0.00 400 0 9,200 0.00 538,364 A-7 1955 to 1984 EARTH MOVEMENT CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,050 8,000.00 14,706.63 450 245,110 6,500 21,413.25 25,904.73 600 575,661 7,100 30,396.20 39,839.60 300 442,662 7,400 49,283.00 46,267.80 300 514,087 7,700 43,252.60 51,740.58 300 574,895 8,000 60,228.55 60,696.33 300 674,404 8,300 61,164.10 61,556,30 300 683,959 8,600 61,948.50 49,472.75 300 549,697 8,900 36,997.00 - _ -- --- 18,498.50 600 411,078 I9,500 0.00 I 4,671,553 A-8 PORTION 2 IN-FILL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 10,426.38 200 77,232 6,500 14,852.75 21,634.60 600 480,769 7,100 28,416.45 27,364.80 300 304,053 7,400 27,120.75 29,789.78 300 330,998 7,700 33,266.40 45,084.85 300 500,943 8,000 56,903.30 56,529.03 I 300 628,100 8,300 56,154.75 38,089.78 300 423,220 8,600 20,024.80 10,012.40 200 74,166 8,800 0.00 0.00 400 0 9,200 0.00 L 2,819,481 A-9 PORTION 3 INFILL BETWEEN 1955 SHORE LINE & 1984 SHORE LINE South of 1955 Shore Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 4,256.63 200 31,531 6,500 5,513.25 5,758.13 600 127,958 7,100 6,003.00 10,663.58 300 118,484 7,400 15,324.15 16,287.08 300 180,968 7,700 17,250.00 15,799.60 300 175,551 8,000 14,349.20 10,237,60 1 300 113,751 8,300 6,126.00 4,333.20 300 48,147 8,600 2,540.40 1,270.20 200 9,409 8,800 0.00 0.00 400 0 9,200 0.00 805,798 4-1 0 1955 to 1987 EARTH MOVEMENT CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,050 8,000.00 . r 16,069.50 450 267,825 6,500 24,139,00 28,311.25 600 629,139 7,100 32,483.50 42,512.15 300 472,357 7,400 52,540.80 56,544.85 300 628,276 7,700 60,548.90 68,168.25 300 757,425 8,000 75,787.60 71,660.43 300 796,227 8,300 67,533.25 I ' 68,096.85 300 756,632 8,600 68,660.45 57,619.48 300 640,216 8,900 46,578.50 23,289.25 600 517,539 9,500 0.00 5,465,636 A-11 PORTION 2 1NFILL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 10,721.13 200 79,416 6,500 15,442.25 20,540.25 600 456,450 7,100 25,638.25 25,975.70 300 288,619 7,400 26,313.15 30,564.53 I 300 339,606 7,700 34,815.90 46,165.25 I 300 F 512,947 8,000 57,514.60 55,528.05 300 ' 616,978 8,300 53,541.50 34,899.50 300 387,772 I I 8,600 16,257.50 8,128.75 200 1 60,213 8,800 0.00 0 I AAA I .UU -tux..? U 9,200 0.00 2,742,001 II A-12 PORTION 3 INFILL BETWEEN 1955 SHORE LINE & 1987 SHORE LINE South of 1955 Shore Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 4,934.00 200 36,548 6,500 6,868.00 5,006.50 600 111,256 7,100 3,145.00 9,234.58 300 102,606 7,400 15,324.15 16,121.08 300 179,123 7,700 16,918.00 15,848.75 300 176,097 8,000 14,779.50 11,099.88 300 123,332 8,300 7,420.25 5,423.88 300 60,265 8,600 3,427.50 1,713.75 200 12,694 8,800 0.00 0.00 400 0 9,200 0,00 801,922 A-13 1955 to 1988 EARTH MOVEMENT CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X Section Square Feet Square Feet Feet Cubic Yards 6,050 8,000.00 15,284.88 450 254,748 6,500 22,569.75 27,824.78 600 618,328 7,100 33,079.80 44,265.50 300 491,839 7,400 55,451.20 56,327.05 300 625,856 7,700 57,202.90 71,417.25 300 793,525 8,000 85,631.60 86,856.55 300 965,073 8,300 88,081.50 85,307.75 300 947,864 8,600 82,534.00 65,103.25 300 723,369 8,900 47,672.50 23,836.25 600 529,694 9,500 0.00 1 5,950,297 A-14 PORTION 2 INFILL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to I Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 10,290.50 200 76,226 6,500 14,581.00 27,529.28 600 611,762 7,100 40,477.55 34,710.33 300 385,670 7,400 28,943.10 30,654.25 300 340,603 7,700 32,365.40 34,723.10 300 385,812 8,000 37,080.80 I _ _ 41,617.15 300 462,413 8,300 46,153.50 f 29,091.50 300 323,239 8,600 12,029.50 6,014.75 200 44,554 8,800 0.00 0.00 400 0 9,200 0.00 2,630,278 A-15 PORTION 3 INFILL BETWEEN 1955 SHORE LINE & 1988 SHORE LINE South of 1955 Shore Average Fnd Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 4,781.75 200 35,420 6,500 6,563.50 4,499.28 600 99,984 7,100 2,435.05 7,784.03 300 86,489 7,400 13,133.00 14,443.50 300 160,483 7,700 15,754.00 14,408.50 300 160,094 - I 8,000 13,063.00 9,767.63 300 108,529 8,300 6,472.25 4,824.63 300 53,607 8,600 3,177.00 1,588.50 200 11,767 8,800 0.00 0.00 1 400 0 9,200 0.00 716,374 A-16 M1ulny M_7 ft'tILAs 1955 to 1995 EARTH MOVEMENT CALCULATIONS PORTION 1 SUBSIDENCE NORTH OF 1955 BLUFF North of Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,050 10,000.00 18,635.25 450 310,588 6,500 27,270.50 33,253.00 600 738,956 7,100 39,235.50 49,942,25 300 554,914 7,400 60,649.00 60,705.50 300 674,506 7,700 60,762.00 78,123.75 300 868,042 8,000 95,485.50 94,068.63 300 1,045,207 8,300 92,651.75 88,653.88 300 985,043 8,600 84,656.00 64,810.50 300 720,117 8,900 44,965.00 22,482.50 600 499,611 9,500 0.00 1 6,396,982 A-17 PORTION 2 INFILL BETWEEN 1955 SHORE LINE & 1955 BLUFF 1955 Shore to Bluff Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 6,000.00 9,115.75 200 67,524 6,500 12,231.50 21,427.88 600 476,175 7,100 30,624.25 24,920.13 300 276,890 7,400 19,216.00 23,271.50 300 258,572 7,700 27,327.00 38,941,50 300 432,683 8,000 50,556.00 42,531.50 300 472,572 `. 8,300 34,507.00 21,259.25 300 236,214 8,600 8,011.50 ^ 4,005.75 200 29,672 8,800 0.00 II 1 0.0WJ 400 0 ] 9,200 0.00 f ? f I 2,250,303 A-18 PORTION 3 I FILL BETWEEN 1955 SHORE LINE & 1995 SHORE LINE South of 1955 Shore Average End Area Distance Volume X-Section Square Feet Square Feet Feet Cubic Yards 6,300 3,000.00 4,312.50 200 31,944 6,500 5,625.00 2,900.00 600 64,444 7,100 175.00 7,153.75 300 79,486 7,400 14,132.50 10,431.00 # 300 11 '' 5,900 7,700 6,729.50 9,740.00 300 108,222 8,000 12,750.50 9,446.75 300 104,964 8,300 6,143.00 4,341.25 300 48,236 8,600 2,539.50 1,269.75 200 9,406 8,800 0.00 0.00 400 0 9,200 0.00 562,603 A-19 C► OSS-SECTION 08/55 and 03/76 in in 43 a� r I v-4 41 z/] a I 500 1955 Cross-Section 400 - 300 — ----,„------+P-- — 200 1976 Cross-Section 100 1976 Cross-Section -- I0 1955 Cross-Section I I CD 0 ® 0 CD a © CD Q ' I - 1 N N m cn mil- '- Horizontal Distance In Feet _.. : 1976 Cross-section above 1955 cross-section INN 1955 Cross-section above 1976 cross-section CROSS-SECTION E 4,176,500 08/55 and 09/84 Ln 01 i 1 e v ° N 6 4cEi Pi 0 A , •0 Ca C/] 3� CZ 0 41 CO 0 Y i N; 500 — 1955 Cross-Section — 400 -- 300 — — 200 — 1984 Cross-Section — 100 — 1984 Cross-Section — 0 — --- 1955 Cross-Section I ! I 'n a In a to o ,--i N N Cf) m d" Horizontal Distance In Feet I'.-,. 1984 Cross-section above 1955 cross-section MEI 1955 Cross-section above 1984 cross-section CROSS-SEC I[ION 08/55 and 01/87 in a) a) cx, V ci 0 0 XI o 0 0 5 -mod r fi 4-44 0et N i c a, PQ H D ,;, 500 — 1955 Cross-Section 300 — 1987 Cross-Section �' 100 — 1987 Cross-Section — 0 1955 Cross-SectionI I I I I - - CD 0 o o 0 o a ® 0 tn o tn o In CD m 7 Horizontal Distance In Feet 1987 Cross-section above 1955 cross-section - 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,176,500 08/55 and 03/88 In cu o r) 11 ;� 0 o ,40 o .1 ci) 0 gLi w cd 0 [4 C O\ - o l- I w 500 4-- 1955 Cross-Section 400 — — 300 — _,�_ 200 s 1988 Cross-Section 100 — - .�- _�. 1988 Cross-Section -- 0 - 1955 Cross-Section I I 1 1 a o Q o o a o In Q i Horizontal Distance In Feet . _ n 1988 Cross-section above 1955 cross-section REINIII 1955 Cross-section above 1988 cross-section CROSS-SECTION E 4,176,500 08/55 and 08/95 au 0\ WI CD CD S=1 0 ,° o VI Cd ca H 703 500 ,- 1955 Cross-Section A 400 — _ 300 200 1995 Cross-Section 100 r 1995 Cross-Section 0 — 1955 Cross-Section I I — I Q N o 0 0 CD o 0 0 in N N m Horizontal Distance In Feet 1995 Cross-section above 1955 cross-section 1955 Cross-section above 1995 cross-section CROSS-SECTION E 4,177,100 08/55 and 03/76 in a as a) in a) pi = `-� ;� r1 pi ': H P cd e p 500 1955 Cross-Section 400 --- 300 1976 Cross-Section 200 — 1976 Cross-Section ` 100 0 I 1955 Cross-Section ! I -� o 0 © 0 0 0 0 c Horizontal Distance In Feet r 1976 Cross-section above 1955 cross-section 1955 Cross-section above 1976 cross-section CROSS-SIEcTioN 08/55 and 09/84 tn In 'am au q ,ma.yy cz, �a.,q m ,a A1 ,1 U] C li 4-4 a> 00 tr) o14 �, 0 7-4 PA Hi 500 — 1955 Cross-Section --� _... 400 300 1984 Cross-Section 200 — � 1984 Cross-Section 100 _ a 1955 Cross-Section 1 cp CD CD CD o 0 0 0 0 CD Horizontal Distance In Feet .° 1984 Cross-section above 1955 cross-section 1955 Cross-section above 1984 cross-section C ii,ISS-SECTION E 4,177,100 08/55 and 01/87 In in 44 t.a) a PI o 0 Cct up cd 4-i r-- m O co In ral o\ C\ - H SDQ 1955 Cross-Section 400 300 1987 Cross-Section 200 1987 Cross-Section 100 ., 0 1955 Cross-Section Horizontal Distance In Feet 1987 Cross-section above 1955 cross-section 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,177,100 08/55 and 03/88 In in cu cn PI 0 n � ' � cia 000 GO � MI Pt 500 -- 1955 Cross-Section co 400 300 1988 Cross-Section `` � 200 A= 100 1988 Cross-Section 0 1955 Cross-Section I I — 0 0 CD o o CD CD CD CD o N c,1 ©m in m .- Horizontal Distance In Feet I,.:_ ., J 1988 Cross-section above 1955 cross-section _ 1955 Cross-section above 1988 cross-section CROSS-SECTION ffffisec E 491/79100 08/55 and 08/95 In N tn N 0 N 41 0 0 0 o xm 0cd in lt) .› 500 1955 Cross-Section `.0 400 300 1995 Cross-Section -.02056165611°-""1.17L 200 ® . �� 100 \ — - 1995 Cross-Section 0 — I7 1955 Cross-Section f I I 1 Horizontal Distance In Feet . 1 1995 Cross-section above 1955 cross-section ® 1955 Cross-section above 1995 cross-section CROSS-SECTION E 4917/ 9400 08/55 and 03/76 in In 0, •pi pi pi p .58 51 Lle a) N 500 1955 Cross-Section 400 300 1976 Cross-Section 200 m 1976 Cross-Section 100 0 ��:. 1955 C ioss-Section ® ® n C C ® C 0 ® kn 0 N ® Cr)In 0 -- Horizontal Distance In Feet 1976 Cross-section above 1955 cross-section 1955 Cross-section above 1976 cross-section CROSS-SECTION E 4,177,400 08/55 and 09/84 In in PI PI o ,° ,4 .5 0 00 tn c p 5004 1955 Cross-Section ___ 300 -� 1984 Cross-Section — 200 "` 100 1984 Cross-Section 0 -- I 1955 Cross-Section I I I I — a o o a Q o 0 0 0 r-a , N N m m e7- 'I''I Ln o Horizontal Distance In Feet .,_,. 1984 Cross-section above 1955 cross-section NEM 1955 Cross-section above 1984 cross-section CROSS-SECTION IE 4,177,400 08/55 and 01/87 Ln in 0 A 0 E In a) oa Inr, C 500 1955 Cross-Section 400 300 1987 Cross-Section - 200 1987 Cross-Section 100 0 I l 1955 Cross-Section I I J CD tn CZ WI CD N N m m '4 in In Horizontal Distance In Feet ..r_.,,: 1987 Cross-section above 1955 cross-section 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,17/y400 08/55 and 03/88 tn o 0 CT coco g g .- z o o 'it C/) C/4 X a) o in crN a` W �a w S00 - 1955 Cross-Section 400 — __ =--_ — 300 — 1988 Cross-Section �� MO — - 1988 Cross-Section 100 — 0 1955 Cross-Section I j I ' — 0 In N N ®Cn m CD in Horizontal Distance In Feet J 1988 Cross-section above 1955 cross-section 1955 Cross-section above 1988 cross-section U CROSS-SECTION E 4,177,400 08/55 and 08/95 r In co o 1 PI 0d 0 ,.q Cr cn 4-, �-, In - CT\ON kn ? M H 50Q 1955 Cross-Section ' 400 — _ 300 1995 Cross-Section 200 10D 1995 Cross--Section 0 - __ 1955 Cross-Section I` I 0 0 c c o Q c) o c O in ® in o m Q N N In CD Horizontal Distance In Feet 1995 Cross-section above 1955 cross-section °- 1955 Cross-section above 1995 cross-section CROSS-SECTION E 491779700 08/55 and 03/76 a 0 0 A A° .0 > � in a) t I A 1955 Cross-Section 500 -- 400 300 — ` 1976 Cross-Section ' — 200 ., -«_Aglirw 100 1976 Cross-Section — — 0 - —` ' 1 1955 Cross-Section I i I 1 —® 0 0 0 0 0 0 © 0 0 0 Horizontal Distance In Feet 1976 Cross-section above 1955 cross-section MEE 1955 Cross-section above 1976 cross-section CROSS-SECTION E 49177,700 08/55 and 09/84 In In 0, a, pi pa P1 'Cl 0 6 a cn v) CD ccs CO t o C 500 1955 Cross-Section r6 400 300 1984 Cross-Section 200 — 100 1984 Cross-Section 0 - 1955 Cross-Section io c) a o 0 0 0 0 0 o Horizontal Distance In Feet 1984 Cross-section above 1955 cross-section .:g: 1955 Cross-section above 1984 cross-section CROSS-SEC II}N E 49177,700 08/55 and 01/87 175 CD CD 0 CD PI In 1-4 °� a'Pi Pi o0 0 0 1.4 ' V] V) fa4 4-4 N vn 0 p 500 1955 Cross-Section 400 - 300 — 1987 Cross-Section 200 --- 100 1987 Cross-Section 0 P 1955 Cross-Section L I .� 0o 0 in 0 CD © CD o - CD CD - N N Cr) c7 Horizontal Distance In Feet kk,„.: 1 1987 Cross-section above 1955 cross-section 1955 Cross-section above 1987 cross-section CROSS-SECTION E 49177,700 08/55 and 03/88 in Lin a) b n) 1-4 0 `-� ;a pf °� a ,o ,° '5 `d › oo Ln o 4 r a� H `'' 500 y—, 1955 Cross-Section — 400 --y., J 1988 Cro ss-Section 1988 Cross-Section 100 — _ _ — 1955 Cross-Section CA CI I-1 1-1I � N m '' in C1 Horizontal Distance In Feet 1988 Cross-section above 1955 cross-section BSIffi 1955 Cross-section above 1988 cross-section CROSS-SECTION E 4,177,700 08/55 and 08/95 In a) •) pi o tit 2 a pi o , , a C1] C/] C � P4 0 ►� 500 1955 Cross-Section w to 400 — 1995 Cross-Section 200 .7 .�LL vii1995 Cross-Section 100 0 - 111110.51r- 1 1955 Cross-Section 1 I I R o a o 0 0 0 o a o Horizontal Distance In Feet ....: 1995 Cross-section above 1955 cross-section _- 1955 Cross-section above 1995 cross-section CROSS-SECTION E 4,178,000 08155 and 03/76 in a> pi rl ` °' b rn PI a) 0 ® 4° • Pk [el > to 0 — ( frl o 500 1955 Cross-Section ., _ " 400 — 300 1976 Cross-Section — - 200 — _ _ 100 - -- 1976 Cross-Section 0 ` I--_--7 i 1955 Cross-Section in 0, 0 0 0 0 0 0 © T9 ,i N N m 'c4. Horizontal Distance In Feet [.' :'-. : 1976 Cross-section above 1955 cross-section 1955 Cross-section above 1976 cross-section th CROSS-SECTION 41/89 IYQID 08/55 and 09/84 in 4) 11 a) 1 4 0 A® A ® ,d a) In W C 0 500 1955 Cross-Section 400 300 00 1984 Cross-Section /100 .---: -- 1984 Cross-Section 0 I 1955 Cross-Section 1 Horizontal Distance In Feet _„__ .,.,._ 1984 Cross-section above 1955 cross-section 1955 Cross-section above 1984 cross-section CROSS-SECTION E 49178'000 08/55 and 01/87 In 0) 01 G PE cl o0 00 0 NLn 0, 0 0 500 1955 Cross-Section 400 \ 300 — 1987 Cross-Section - - 200 — — _ Cross-Section 100 -- 0 ' Cross-Section ono o o no 0 0 © o tn ra e r N n O cr) oo Horizontal Distance In Feet E 1 1987 Cross-section above 1955 cross-section 1 ,x, 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,178,000 08/55 and 03/88 in tn pi o 44 'o rn C/a n 1 500 a— 1955 Cross-Section �' 400 300 1988 Cross-Section } - 200 100 - 1988 Cross-Section .� 0 1955 Cross Section In c) CD o 0 0 0 0 In 00 O N N Cr) Horizontal Distance In Feet , .., :, 1988 Cross-section above 1955 cross-section a 1955 Cross-section above 1988 cross-section CROSS-SECT1°IN E 4,178,000 08I55 and 08/95 vn in -I 0 .E td 0 0 Cr) Cr) It f-t el 0 In In 500 1955 Cross-Section 400 Z001995 Cross-Section 100 1995 Cross-Section 1 1955 Cross-Section Il L f I I �, • in as 0 0 o 0 0 in 0 0 0 in 0 c� N cc) m d- din f- Horizontal Distance In Feet I :I 1995 Cross-section above 1955 cross-section 1955 Cross-section above 1995 cross-section CROSS-SECT1ON E 4,178,300 08/55 and 03/76 in a a� in 0 in-4 1-4 ocd o 44 cd `�° • H 500 - 400 1955 Cross-Section 300 1976 Cross-Section `� 200 0 1955 Cross-Section ip Plane 1976 Cross-Section Sl in 0 in 00 0 0 0 0 0 0 0 Horizontal Distance In Feet I,• usf 1976 Cross-section above 1955 cross-section 4; 1955 Cross-section above 1976 cross-section CROSS-SECTION E 4,178,300 08/55 and 09/84 In ON o ,-go 0 1-4 ci) VD a4 o v co un = P 500 1955 Cross-Section — 400 — — 300 - £..a. 200 1984 Cross-Section — { µ 9 1 84 Cross-Section -� 100 . - , ' 1955 Cross-Section Slip Plane iiiillin 0 0 0 0 0 0 0 0 0 in O N N O m Horizontal Distance In Feet _LL,. _ I 1984 Cross-section above 1955 cross-section MEV 1955 Cross-section above 1984 cross-section C rl OSS-SECTION E 49178 300 08/55 and 01/87 In In F4 PI O a •1 > N Ln o P 500 — 1955 Cross-Section -- 400 — 300 1987 Cross-Section �---- - — 200 ® ,— '"'`� 100 1955 Cross-Section Slip Plane 1987 Cross-Section C I L. 1 Horizontal Distance In Feet 1987 Cross-section above 1955 cross-section EME 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,178,300 08/55 and 03/88 in un 0 0 ,- '0 V) Ed 0 0000 M 01 01 - n H 500 — 400 — 1955 Cross-Section 300 — _ (('��(("�� Cross-Section --.= �~ — 100 — ,- - 0 '''''a'''''' 1955 Cross-Section Slip Plane 1988 Cross-Section — 0 CD o o 0 o 0 o CD In Q in N Q m N Horizontal Distance In Feet :::: h= 1988 Cross-section above 1955 cross-section MI 1955 Cross-section above 1988 cross-section Cri.OSS-SECTION E 491789300 08/55 and 08/95 in In 4) a) cn 4) 0 ro 0 C� � CI) i�1 0 tn In VI 0\ C\ -. 0 0 H 1 Lo 500 1955 Cross-Section 400 -- 300 _ 1995 Cross-Section 200 1 100 1995 Cross-Section 0 1955 Cross-Section Slip Plane Horizontal Distance in Feet 1995 Cross-section above 1955 cross-section 1955 Cross-section above 1995 cross-section CROSS-SECTION E 4,178,600 08/55 and 03/76 In In a) a) 0 0 o 4 et CD o 0 500 — 1955 Cross-Section 400 300 — 1976 Cross-Section 200 — 100 1976 Cross-Section ___ 0 — 1955 Cross-Section _ 1 1 w I i ! © 0 0 ® o ® Q © e ms e,] N tn O m 'In t in - Horizontal Distance In Feet ,:. 1976 Cross-section above 1955 cross-section NMI 1955 Cross-section above 1976 cross-section CROSS SECTJON E 4,178,600 08155 and 08/84 In In a) a.) 4 a) cl) PI l mt 1-1 o ,. ,= al Cl) Cl) � In O in 01 ONXi0 n 500 1955 Cross-Section 400 300 —a 1984 Cross-Section '- — 200 4-�t 100 1955 Cross-Section 1984 Cross-Section 0 e. [ - Horizontal Distance In Feet f:; 1984 Cross-section above 1955 cross-section ' ':: 1955 Cross-section above 1984 cross-section CROSS-SECTION E 4,178,600 08/55 and 08/87 tn a • C �° ,--1 0 a N ►n In Wcp, Si - 0 f :1 500 - 1955 Cross-Section 400 — _ 300 — 1987 Cross-Section 200 1 _ 100 1955 Cross-SectionT170si0n I_ I to CD fn N cam*) CD Lt) ,.1- Horizontal Distance In Feet ;,..; 1987 Cross-section above 1955 cross-section ' ___ ___. 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,1789600 08/55 and 08/88 In ®, CD F 0, 500 1955 Cross-Section 400 300 h. 1988 Cross-Section 200 r 100 ] '4°' N _ I955 Cross-Section 1988 Cross-Section 0 ' -- __. F © ® 0© © © © CD CD CD In C C © m C Horizontal Distance In Feet __ 1988 Cross-section above 1955 cross-section MIN 1955 Cross-section above 1988 cross-section CROSS-SECTION E 4,178,600 08/55 and 08/95 in a a) a) In a) w a i4 -o ,� v � *� 0 G ca A - A �0 r� w+ V) V) lea in I 0. r4 500 1955 Cross-Section 400 - -'" 300 ® 1995 Cross-Section 200 —_ �-� 100 — '' — _ 1995 Cross-Section .,- 1955 Cross-Section i a - _ 1 _ I I I I o 0 0 0 0 o © o 0 0 Horizontal Distance In Feet Y:'::`:a 1995 Cross-section above 1955 cross-section NEW 1955 Cross-section above 1995 cross-section CROSS-SECTION E 4,178,900 08/55 and 03/76 In CU v 01 o gZi 4 o m- CQ) Cf) ct 0 i ch l °+ ° H Lri 500 — 1955 Cross-Section 300 200 — 100 — 1976 Cross-Section o � __I I I I 1 I I I © © © © © © © © in Q ® © © © © © © © in N in O 1-4 N N CD NT 00 � Horizontal Distance In Feet 1976 Cross-section above 1955 cross-section IMM 1955 Cross-section above 1976 cross-section CROSS-SECTION E 4,178,900 08/55 and 09/84 to Ln o o A° cn• La �-, 0 C H 500 1955 Cross-Section 1 400 300 200 100 - - - _ 0 _ 1984 Cross-Section I I I I I I _ I I — c) c) cD CD C 0 b 0 C C O ►n O 0 CDC CD CD © CO O In N to O in CD In ?cl in 00 1 N C N•1 ® m Horizontal Distance In Feet I'": .: I 1984 Cross-section above 1955 cross-section -. _ , -'.; 1955 Cross-section above 1984 cross-section CROSS-SECTION E 491789900 08/55 and 01//87 In In 4 pi 1-4 N In o WT-1 XI 0 H 1 500 1955 Cross-Section I 400 — — 30(0 — �� ,,t 20V may^M_s- ,-- a a F?' 100 — -- _ 0 1987 Cross-Section I _I 1 O C) C) C) C? ® C) C) © 0 C) In C, cD 9 CD (7) C) C ) 0 C) 0o.n Q In 0 in 09 m m Horizontal Distance In Feet _. . 1987 Cross-section above 1955 cross-section MEM 1955 Cross-section above 1987 cross-section CROSS-SECTION E 4,178,900 08/55 and 03/88 In kn va 0 ,t 0 r.01 •O 00 Pd 4-4 cd 00 I O ) - 0. GI o H T' co 500 — 1955 Cross-Section 400 300 — =-- -. 0 I P I I I I I 1988 Cross-Section I 0 0 0 0 0 0 0 0 0 0 cD `n 0 0 C . 0 0 0 0 0 0 try N to O in N N Q cn O in 00 Horizontal Distance In Feet .�.::w:i 1988 Cross-section above 1955 cross-section Iffilil 1955 Cross-section above 1988 cross-section CROSS-SECTION E 4,1789900 08/55 and 08/95 in cA pi cr, CA 0 i' 500 - 1955 Cross-Section I 400 -- - 300 - . . 200 100 a 1995 Cross-Section i I I I 1 f I I I -- CD CD CD tn eNi In Q N N o In Horizontal Distance In Feet 1995 Cross-section above 1955 cross-section MEE 1955 Cross-section above 1995 cross-section