Mechanical Engineering Safety Seminar 2017

1. Engineering Testing of Mine
Tailings Dams

2. it’s a weird environment

3. 70 projects

15. softer softer softer softer

17. click below

18. finish weird
environment

19. Engineering Testing of Mine
Tailings Dams
Why do we test this stuff?

20. Engineering Testing of Mine
Tailings Dams
(1) design of raisings

21. three
ways to
raise a
tailings
dam

23. Fundao Dam - Samarco

24. 18

26. slip failure

29. strength, density, permeability, etc

31. this is not at all rare

34. around 120 listed major failures since 1961

41. third world countries ??

42. third world countries ??

43. 2014 - USA

46. 2015 - Canada

48. USA China Myanmar Brazil Mexico Canada USA Armenia
Canada Canada Finland China Hungary Peru Russia China

49. USA China Myanmar Brazil Mexico Canada USA Armenia
Canada Canada Finland China Hungary Peru Russia China

51. BHP & Vale

55. at least 17 people dead

58. Some Early Warnings of
Potential for Failure of
Fundão Dam
58
Piping at downstream slope
of Dyke 1, 13 April 2009
Seepage, cracking and slumping
at left abutment on 15 November 2013
Cracks on dam crest and saturation at toe on 27 August 2014

59. Samarco, Brazil, Google
Earth View of Hydro Dam
Before and After
59
Before – 26 August 2014After – 12 November 2015

61. 600km from mine to sea

63. Samarco, Brazil, Google
Earth View of Rio Doce
Mouth Before and After
63
Before – 23 May 2014After – 1 December 2015

64. finish reason 1

65. Engineering Testing of Mine
Tailings Dams
(2) design of closure

76. softer softer softer softer

77. softer softer softer softer
constructability ???

83. finish reason 2

84. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment

85. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment

88. weird
guys

89. Sergey

114. Philippines

117. Glen

118. Thailand

124. Glen - again

126. Warkworth

127. Warkworth

128. Cloncurry

129. Mt Thorley

130. Ravensworth

139. almost
liquid

141. assessing
access

143. 0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
0.800
0.0000.5001.0001.5002.0002.500
depth(m)
qc (MPa)

145. click here

148. • It is designed to operate safely in an
environment where "to bog is not bogged".
• It can traverse to its traffickability limits then
recover easily and safely.
• Permitting CPTu testing and Vertek Sampling
in very soft materials in situations that are not
accessible by any other means.

152. finish weird
machines

155. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment

160. elevated pore pressure
u here
may be
smaller
than u
here
If the “system” is
“soft”, a tiny amount of
pore fluid must flow to
transmit the pressure

164. 72 hours in heated glycerol under 99% vacuum
vibrated randomly

170. STOP
DESATURATION

171. IGS Plot
Format

172. cone
cone x 10

173. sleeve
sleeve x 10

174. sleeve / cone

175. pore pressure

176. Scales Ratio
Sleeve vs Cone
1/20 = 5%

180. pore pressure
?

182. enhanced soil
identification

183. qt (kPa)
elevated pore pressure u=u+Δu (kPa)
pore pressure changed by
soil shearing

185. clay
u2 position
99.99% of tests

186. sand

187. dilatant
-ve
+ve

191. PPDTs

192. slow draining

193. dissipation tests

195. 300 seconds
= 5 minutes

197. 50,000 seconds
= 14 hours

198. 50,000 seconds
= 14 hours
50,000 seconds
= 14 hours
300 seconds
= 5 minutes
300 seconds
= 5 minutes
?

199. sleeve
friction
cone
resistance
pore
pressure
thrust from
test rig
nice
example

209. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment
more

212. 360 deg = 1 hour360 deg = 1 hour

215. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment
more

216. Marchetti’s Dilatometer (DMT)

222. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment
more
things

226. PPI SAMPLER
•IGS design (unique)
•316 stainless
•stationary piston
•63mm OD x 1.6mm wall
•area ratio = ~10%
•nil pull-out suction
•sample anything soft

227. Warkworth

229. finish weird
tests etc

230. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment

231. Engineering Testing of Mine
Tailings Dams
Weird Tests And Weird
Machines Are Used In This
Weird Environment
finish weird
presentation