363:. This allows for the direct measurement of total hydraulic head, thus accounting for the total energy loss between the upstream and downstream ends of the soil sample. While the diameter of the hole is still not measured directly throughout the test, the pitot-static tube provides an independent estimate of the mean flow velocity, which can then be used to calculate the diameter of the hole more directly using the
430:
187:
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is negligible, which may not be a valid assumption given the sometimes high velocities downstream of the hole. The difference in hydraulic head used to calculate the shear stress also does not factor in the
455:
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and expansion losses downstream of the test specimen. Furthermore, estimating the diameter of the hole throughout the test using an assumed friction factor has been reported as problematic.
370:
The modified hole erosion test results in significantly smaller values for the critical shear stress - this is makes the results of the test more consistent with other tests, such as the
294:
75:
forms and erosion begins. The numerical measure of soil erodibility can be used to predict how quickly this erosion will progress, and it can be found as an input in various
232:. From the change in diameter of the hole over time, the rate of erosion can thus be plotted against applied hydraulic shear stress and fit to the following equation:
543:
228:
While the diameter of the hole is not directly measured throughout the test, it can be estimated using the measured flow rate as well as an estimated
518:
Wahl, T L; Regazzoni, P; Erdogan, Z (2008). "Determining
Erosion Indices of Cohesive Soils with the Hole Erosion Test and Jet Erosion Test".
131:
456:"WinDAM C: Analysis tool for predicting breach erosion processes of embankment dams due to overtopping or internal erosion"
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should be measured throughout the procedure. Directly after the test, the diameter of the hole should be measured.
237:
504:
111:. As the liquid (typically water) flows through the hole, the soil should erode and the hole will expand. The
24:
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520:
Hydraulic
Laboratory No. DSO-08-05, US Dept. of the Interior, Bureau of Reclamation, Technical Service Center
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Luthi, Marcel; Fannin, R Jonathan; Millar, Robert G (2012). "A modified hole erosion test (HET-P) device".
416:
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229:
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One criticism of the standard hole erosion test is that the use of the hydraulic head rather than the
112:
454:
Hunt, Sherry L; Temple, Darrel M; Neilsen, Mitchell L; Ali, Abdelfatah A; Tejral, Ronald D (2021).
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76:
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Wan, Chi Fai; Fell, Robin (2004). "Investigation of Rate of
Erosion of Soils in Embankment Dams".
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of embankment dams, the critical shear stress provided by this test indicates the maximum
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is set to a standard value, and the initial upstream hydraulic head is chosen using
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Geotechnical engineering method used to quantify resistance of soil to erosion
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182:{\displaystyle \tau =\rho g{\frac {\Delta h}{L}}{\frac {\Phi _{t}}{4}}}
501:
Experimental
Investigation of Erosion in Variably Saturated Clay Soils
56:
503:. Sydney, Australia: School of Civil and Environmental Engineering,
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mm) is drilled lengthwise through the soil. Next, the downstream
28:
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on a remolded soil sample, and provides estimates of both the
359:(HET-P) seeks to rectify these issues with the addition of a
405:
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is the difference in hydraulic head across the sample,
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of the soil sample as well as a numerical measure of
288:
181:
91:The standard hole erosion test consists of first
35:, and is specifically relevant to the topic of
71:(such as water) can apply to a soil before a
8:
289:{\displaystyle E_{r}=k_{d}(\tau -\tau _{c})}
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417:10.1061/(ASCE)1090-0241(2004)130:4(373)
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122:along the surface of the hole at time
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222:is the diameter of the hole at time
544:Tests in geotechnical laboratories
460:Applied Engineering in Agriculture
331:Modified hole erosion test (HET-P)
305:is the rate of erosion over time,
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150:
14:
325:critical shear stress for erosion
215:is the length of the sample, and
99:. Then, a small hole (typically 6
49:critical shear stress for erosion
43:. The test can be performed in a
27:to quantify the resistance of a
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95:the soil sample in a standard
1:
482:Geotechnical Testing Journal
339:implies that the change in
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357:modified hole erosion test
205:gravitational acceleration
23:(HET) is a method used in
505:University of South Wales
25:geotechnical engineering
435:www.hec.usace.army.mil
431:"Transport Parameters"
372:Rotating Cylinder Test
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126:can be calculated as:
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238:
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77:computer simulations
522:. Denver, Colorado.
365:continuity equation
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499:Lim, S S (2006).
419:– via ASCE.
361:pitot-static tube
346:energy dissipated
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73:concentrated leak
21:hole erosion test
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376:Jet Erosion Test
314:soil erodibility
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53:soil erodibility
37:internal erosion
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109:trial-and-error
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41:embankment dams
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411:(4): 373–380.
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118:The hydraulic
105:hydraulic head
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488:(4): 660–664.
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466:(3): 523–534.
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539:Soil erosion
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438:. Retrieved
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348:due to flow
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120:shear stress
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65:shear stress
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81:dam failure
61:engineering
533:Categories
440:2024-05-28
382:References
337:total head
93:compacting
45:laboratory
275:τ
271:−
268:τ
166:Φ
151:Δ
142:ρ
136:τ
113:flow rate
87:Procedure
55:. In the
374:or the
323:is the
312:is the
203:is the
197:density
195:is the
67:that a
33:erosion
316:, and
298:where
191:where
101:
57:design
69:fluid
355:The
97:mold
79:for
59:and
29:soil
19:The
413:doi
409:130
378:.
39:in
31:to
535::
486:35
484:.
472:^
464:37
462:.
458:.
433:.
407:.
389:^
367:.
327:.
224:t.
209:Δh
207:,
83:.
507:.
443:.
415::
320:c
318:τ
309:d
307:k
302:r
300:E
284:)
279:c
265:(
260:d
256:k
252:=
247:r
243:E
219:t
217:Φ
213:L
201:g
193:ρ
175:4
170:t
158:L
154:h
145:g
139:=
124:t
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