Construction and Monitoring of Cement/Bentonite Cutoff Walls: Case Study of Karkheh Dam, Iran

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Comparison between numerical and piezometric pore-water surface resulting from transient analysis_

Reservoir	156.87
Level(m)
Time	3 DAY			3 DAY		3 DAY		3 DAY		38 DAY
steps	dt = 3600s			dt = 4800 s		dt = 5400s		dt = 7200s		dt = 4800s
Ins. No.	Measured pore-water surface	Calculated pore-water surface	Fault (%)	Calculated pore-water surface	Fault (%)	Calculated pore-water surface	Fault (%)	Calculated pore-water surface	Fault (%)	Real pore-water surface	Calculated pore-water surface	Fault (%)
EP 4-1	143.28	191.94	-33.96	190.61	-33.03	189.29	-32.11	186.88	-30.43	144.69	189.35	-30.87
EP 4-2	166.42	192.32	-15.56	191.36	-14.99	190.44	-14.43	188.55	-13.29	166.51	190.43	-14.36
EP 4-3	182.16	192.01	-5.41	191.63	-5.20	191.23	-4.98	190.31	-4.47	182.22	191.21	-4.94
EP 4-4	172.85	177.25	-2.55	177.01	-2.40	176.74	-2.25	176.09	-1.88	171.81	176.71	-2.85
EP 4-5	172.45	173.27	-0.47	173.07	-0.36	172.86	-0.23	172.31	0.08	172.89	172.83	0.03
EP 4-6	155.23	165.06	-6.34	164.85	-6.20	164.62	-6.05	164.05	-5.68	154.18	164.59	-6.76
EP 4-7	183.65	161.21	12.22	160.99	12.34	160.76	12.47	160.19	12.77	182.01	160.73	11.69
EP 4-11	219.09	193.36	11.75	193.01	11.90	192.31	12.22	191.63	12.54	187.24	192.64	-2.89
EP 4-12	199.10	186.20	6.48	186.16	6.50	186.06	6.55	185.99	6.59	198.99	186.12	6.47
EP 4-13	199.69	176.65	11.53	176.65	11.54	176.64	11.54	176.62	11.55	199.76	176.64	11.57
EP 4-15	185.01	197.03	-6.50	196.57	-6.25	195.26	-5.54	194.29	-5.01	185.03	196.09	-5.97
EP 4-16	196.04	196.31	-0.14	196.15	-0.05	195.47	0.29	195.39	0.33	195.71	195.98	-0.14
EP 4-17	190.37	194.40	-2.12	194.35	-2.09	194.18	-2.00	194.14	-1.98	191.09	194.30	-1.68
EP 4-19	189.73	180.00	5.13	180.01	5.13	180.01	5.12	180.04	5.11	191.43	180.01	5.97
RP 4-2	123.36	137.84	-11.74	137.00	-11.06	136.22	-10.43	134.81	-9.28	124.07	136.25	-9.82
RP 4-3	149.93	189.91	-26.67	188.35	-25.63	186.84	-24.62	184.18	-22.85	151.32	186.93	-23.54
SP 4-1	140.88	193.04	-37.02	191.77	-36.13	190.49	-35.22	187.97	-33.43	144.30	190.50	-32.02
SP 4-2	149.80	192.43	-28.46	191.16	-27.61	189.90	-26.77	187.52	-25.18	151.47	189.94	-25.40
SP 4-3	195.17	185.44	4.99	185.37	5.02	185.28	5.07	185.09	5.17	194.98	185.29	4.97
SP 4-5	185.62	191.82	-3.34	191.63	-3.24	191.23	-3.02	190.86	-2.82	184.50	191.42	-3.75
SP 4-6	202.01	193.58	4.17	179.63	11.08	179.60	11.09	179.54	11.12	202.08	179.60	11.12

Drilling mud properties of the cutoff wall of Karkheh Dam

PH	Bentonite Cake (mm)	Gel Resistance after 10 Minutes (g/cm3)	Filtration Losses (cm3)	Density (g/cm3)	Marsh Funnel Viscosity (s)
7~10	<3	60~75	<30	1.04~1.10	32~50

Mix proportion design of a cubic meter of plastic concrete of the Karkheh Dam cutoff wall_

f'c−28${{f'}_{c-28}}$days MPa	4.02
f'c−7${{f'}_{c-7}}$days Mpa	2.30
Slump mm	180~190
sand 0~5 kg	780
gravel 0~9.5 kg	294
gravel 9.5~19 kg	555
wc$\frac{w}{c}$	1.425
Bentonite kg	25
cement kg	200

Comparison between numerical and piezometric pore-water surface resulted from steady-state analysis_

Reservoir Level(m)	175.49			193.56			201.00			210.37
Instrument No.	Measured pore-water surface	Calculated pore-water surface	Fault (%)	Measured pore-water surface	Calculated pore-water surface	Fault (%)	Measured pore-water surface	Calculated pore-water surface	Fault (%)	Measured pore-water surface	Calculated pore-water surface	Fault (%)
EP4-1	163.27	185.62	-13.69	167.77	192.88	-14.97	172.18	196.14	-13.91	177.31	200.37	-13.00
EP4-2	179.00	184.93	-3.32	202.78	191.67	5.48	202.55	194.71	3.87	201.93	198.67	1.62
EP4-3	194.73	183.51	5.76	195.18	189.07	3.13	199.40	191.56	3.93	203.15	194.79	4.12
EP4-4	181.56	171.64	5.46	182.33	175.50	3.74	185.83	177.24	4.62	189.36	179.50	5.21
EP4-5	184.16	168.80	8.34	195.53	172.01	12.03	201.77	173.46	14.03	209.26	175.34	16.21
EP4-6	157.64	161.79	-2.64	156.87	164.10	-4.61	159.72	165.14	-3.40	162.44	166.50	-2.50
EP4-7	170.47	158.62	6.95	175.83	160.76	8.57	177.14	161.73	8.70	179.98	163.00	9.43
EP4-11	202.49	183.83	9.22	201.27	191.02	5.10	203.87	194.50	4.60	206.98	199.19	3.76
EP4-12	207.42	178.36	14.01	210.98	183.66	12.95	211.25	185.85	12.02	212.51	188.77	11.17
EP4-13	208.94	171.54	17.90	211.10	174.76	17.21	210.97	175.62	16.75	211.84	176.63	16.62
EP4-15	173.20	186.78	-7.84	191.87	195.00	-1.63	199.20	199.63	-0.22	209.01	206.23	1.33
EP4-16	209.84	185.71	11.50	204.90	193.18	5.72	205.83	196.90	4.34	206.60	201.87	2.29
EP4-17	203.02	185.25	8.75	198.15	191.69	3.26	197.72	194.64	1.56	197.19	198.04	-0.43
EP4-19	208.79	175.79	15.80	197.94	180.27	8.93	196.90	181.49	7.83	196.36	181.72	7.46
RP4-2	132.47	140.24	-5.86	131.97	140.65	-6.58	133.45	140.83	-5.53	135.13	141.06	-4.39
RP4-3	169.98	187.24	-10.15	186.22	191.72	-2.95	192.20	193.69	-0.77	200.11	196.22	1.94
SP4-1	156.72	180.59	-15.23	164.90	191.30	-16.01	168.32	195.88	-16.38	172.76	201.73	-16.77
SP4-2	171.63	186.80	-8.84	189.06	193.12	-2.15	196.03	195.98	0.03	204.14	199.69	2.18
SP4-3	208.39	178.83	14.19	206.49	183.74	11.02	208.35	185.97	10.74	209.20	188.93	9.69
SP4-5	204.02	183.58	10.02	204.92	189.56	7.49	207.55	192.42	7.29	207.95	196.24	5.63
SP4-6	217.79	174.74	19.77	212.81	177.94	16.39	213.85	179.03	16.28	213.67	180.46	15.54

Plastic concrete properties of the cutoff wall_

3~7 MPa	Compressive Strength
1×10-8 m/s	Permeability
500~1000 MPa	Young’s Modulus
170~220 mm	Slump