Upload
cassindy
View
362
Download
5
Embed Size (px)
Citation preview
1. Flexible retaining structure for evaluation of debris-flow hazards mitigation NSC 95-2622-E-324-009 95 11 01 ~ 96 10 31 Abstract The retaining structure adopted by this research has both functions of a permeably flexible energy dissipation structure and a previous rock gabion dam. As it is not full of soils and sediments in the retaining structure, then it is the function of flexible energy dissipation structure. As it is full of soils and sediments in the retaining structure, then it becomes the function of rock gabion dam naturally. In coordination with the Program to Upgrade Industrial Technology and Enhance Human Resources of National Science Council, we set up an on-site debris-flow retaining structure in the upstream of Shan Pu Keng River, Shanan Village, Shueili Township, 0.3 Nantou County to assess the effect of such 0.450.55debris-flow retaining structure and to shrink its size to move to the indoor for a test of 80%0.35debris-flow tank. 60.3%For the volume concentration reduction rate, the result of indoor tank test shows that the volume concentration for all cases after passing 40%the dam is reduced to below 03.As the initial 0.65 volume concentration is 0.45 and 0.55, the 98.88%0.35volume concentration reduction rate is more than 80%.For the initial volume concentration 60% of 0.35, then the reduction rate is 60.3%.The dam-passing rate will be reduced as increasing the volume concentration, which is less than 40% before the dam reaches the full level. The higher the volume concentration is, then the better the grain deposition rate is. As the volume concentration is 0.65, the grain deposition rate can reach 98.88%. And as the1 2. volume concentration is 0.35, the grain (a) deposition rate will be down to 60%. Under the(b)(c)(d)(e) strike of debris-flow again and again, we use the displacement meter and the vibration meter to measure the impact fore of sediments in the auxiliary dam and in front of the dam and the acceleration of sediments in the dam and find that they are significantly reduced. Therefore, through the test, we can find that we can truly make use of the characteristics of a retaining structure to retain & deposit the debris flow. Key WordDebris Flow, Flexible RetainingStructure, Volume Concentration Reduction Rate, Dam-passing Rate, Grain Deposition Rate 2-1 2.1 2.2 1992 2-12.3 2-2 (a)(b) (c)(d)(e) 2-2 2 3. 1980 (grid-type sabo2.4 dam) 2-3 L / Dmax =1.5 2.0 (1999) L / Dmax L1 2 1 DmaxE= mv + I 2 (2-3) 2 2m [kg] MassLLL L v [m/s]VelocityI [mkg]Rotation Mass of Inertia 2-3 [l/s]Rotation Velocity1989 L Dmax (Impluse) (1) C p C p L / Dmax pFav = (2-4) t (2) L R (%)p = t t =R = 53.4318(L / Dmax ) 0.81601(2-1) Fav =t R (3) Qp L = 0.6126 + 0.6429 D (2-2) Qw max Q p Qw (4) (5) L / Dmax < 2.0 3.13.1.1 E k ()50% E k 1 Ek 13 4. 8.22 1957 23 3-1 5.12 ( ) 3600 960 411 19 334 15 147 1420 071 3-1 3-2 3-1 (kg)1173.5 (m3)0.576 (t/m3) 2.037 (t/m3) 1.917 (%) 5.0 (%)77.6 #200 (%) 4.1 3-1 0.1mm (%) 5.3 - NP 3.1.2 - NP 3.3 3-3 7.5m 6m( ) 3m 4.5m 50cm 40cm 80cm120cm 3.2 1m 4 5. 3-4 3-5 (96.08.12~96.08.14) 3-3 8 14 2/3 ( 2m) 1/4 ( 40cm) 3-6 3-4 3.4 96 8 6 8 8 3-6 (96.08.14) 96 8 8 8 9 8 13 101.5mm 3-5 50m 12m 15m 3-7 4m 8~10 20~30cm 14~16 50~60cm 1m 3-7 (96.08.14)5 6. 8 12 8 13 7 25 (1) 40 cm 40 cm 600 cm 420 cm 19.5cm#4 8cm 032 4.1 4-2 (2) 130 1980 grid-type sabo dam L / Dmax =1.5 2.0 L / Dmax 124 2"1"0.5"(3) 4-1 320 cm 200 cm 10 cm #4 #4 4-3 #4 0.1mm 5.3 % 1991 0.1mm 10 % 100 90 2" 801" (%) 0.5" 70 4-2 60 50 40 30 20 10 01000 100 101 0.10.01(mm) 4-1 4.2 4-3 4.2.1 6 7. 4.2.2 Test10.65 231" 3 Test20.55 232" 3 Test30.65 232" 3 Test40.6231" 3 30cm 5.08cm(2")Test50.55 231" 3Test60.45 231" 4 15cm 30cm Test70.35 231" 42.54cm(1") Test80.55 23 0.5"4Test90.45 23 0.5"4 40cm 30cm Test10 0.35 23 0.5"4 2.54cm(1")4.3.2 30cm 2.54cm(1") (1) LVDT (2)() (3) 4-4 ( 30 ) 11 3 (4) mm (5) 34 (6) 5.1 4-5 34 5-1 4.3 5.2 4.3.1 4-1 4-1 7 8. C0 C1 5-3 RV = 100% C0 C0 C1 0.35 0.5" 1.2 0.45 0.5"10.55 0.5"(%) 0.8 0.60.4 0.2 0 01 23 4 5 5-1 5-4 (Dmax=0.5")1.20.35 1"0.45 1" 1(%)0.55 1" 0.80.60.40.20 01 23 4 5 5-5 (Dmax=1") 5-2 5.4 Rp V0 V1Rp V1 5-3 RP =100% V0 5.3 Rv V0 V1 Rv Rv 8 9. 45% 100%40%95% 35%90%30% %25% 85%%20% 80%15%75%10%70%5%0%65%0.3 0.35 0.4 0.45 0.50.55 0.60.65 0.7 60%Cv0.3 0.35 0.4 0.450.5 0.550.6 0.650.7 5-6 Cv 5-7 0.35 40.25% 0.65 5.6 1.13% 0.35 5.5 - LVDT Excel 5-8 6%42% =L1-L2/L Rs Test 4 80T RS =100% 70 T +P 60 LVDT (mm) 50 T40P30 20 10 0.45 0 90% 0.35 -10 11.52 2.53 3.5 4 4.5 60.0% 5-7 (s) 0.45 5-8 0.450.35 91.6%~98.9% 60% 5.7 5-95-11 X 9 10. 3. 0.262(cm/s2) 0.054(cm/s2) 0.016 (cm/s2) 0.35 40.25% 0.65 1.13% 1 Test 3 X 0.35 0.5 Vlot 04. -0.5 0.45 90%-1 0.35 0 0.51 1.52 2.5 3 3.5 4sec60.0% 5-9 5. 1Test 3 X0.5 lot0 V-0.5 -1 0 0.51 1.52 2.5 3 3.5 4 6%~42%sec 5-10 0.262(cm/s2)Test 3 1 X 0.5 0.054(cm/s2) 20.016 (cm/s )lot 0 V-0.5-1 00.5 1 1.5 22.5 3 3.5 4 sec 5-11 ( NSC 95-2622-E-324-009-CC3) 1. 1. - 2.. 185 1992 2. No.114 37-44 19803. 10 11. No.20B-2 1-31 1977 4. ()87 1998 5. 45 2000 6. 1994 7. No.23B-2 1980 8. () No.1391993 9. No.74 21-28 1999 10. 1989 11. 1999 12. Johnson, A.M. and Rodine, J.D., Debris Flow, Slope Instability, John Wiley & Son Ltd., pp. 257-361,1984. 13. Halliday, D. and Resnick, R.,Fumdamentals of physicsJohn Wiley & SonsInc. pp.102~103N.Y., 1970. 14. Timoshenko, S., Strength of Materials, Partl1 Elementary Theory and Problems, D.Van Nostrand Company, Inc.,pp.301~302,N.Y., 1956.11