Hydraulic Characterization of a Self-Weight Compacted Coal

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Physical-volumetric parameters of the coal cylindrical samples: a) at initial state; b) after imbibition

a)
Sample	w0	γ0 (kN/m3)	Gs*	γd (kN/m3)	e0	Sr	θ	drying procedure / time (day)
1	15.9%	8.4	1.2	7.2	0.63	30%	0.12	hygroscopic / -
3	9.7%	8.5	1.2	7.8	0.52	23%	0.08	free drying / 2
2	7.7%	8.5	1.2	7.9	0.49	19%	0.06	free drying / 4
4	0.0%	7.7	1.2	7.7	0.52	0%	0.00	oven drying at 105°C / 2

Matric suction values measured along the central vertical of the prototype model: a) at initial state; b) during the drying phase

a)
ch1	ch2	ch3
(kPa)	(kPa)	(kPa)
61.9	56.3	65.1

Hydraulic function parameters: a) at the first infiltration test; b) at the second infiltration test

a)
θr	θ0	α	a=1/α	n′	ks	l
		(kPa)−1	(kPa)		(m/s)
0.0165	0.3014	1.670	0.598	1.703	8.0E-04	1

Compositional data of the coal

Determination	Standard/Method	Weight (%)	Note
Moisture in the Analysis Sample*	ISO 11722:1999	11.1	Air Dried Basis
Ash Content*	ISO 1171:2010 (E)	5.8	As Received Basis
Volatile Matter*	ISO 562:2010 (E)	37.4	As Received Basis
Fixed Carbon*	By calculation	42.3	As Received Basis
Carbon**	ASTM D 5373-08	65.7	Air Dried Basis
Hydrogen**	ASTM D 5373-08	4.4	Air Dried Basis
Nitrogen**	ASTM D 5373-08	1.3	Air Dried Basis
Sulphur**	ASTM D 4239-10	0.8	Air Dried Basis
Oxygen**	By calculation	10.7	Air Dried Basis

Hydraulic properties of the Indonesian coal in comparison to other granular materials

Material	a (kPa)	ks (m/s)
Indonesian Coal – virgin state(present study)	0.60	8.0E-4
Indonesian Coal – after collapse(present study)	1.23	1.0E-5
Silty Clayey Sand(Cafaro et al. 2008)	0.63	1.58E-6
Pervious Concrete – different mixtures(Marzulli et al. 2018)	3.071.56	2E-45E-3
Sand(Lu and Likos 2004)	10	3E-4

WRC parameters for the drying phase following the first imbibition stage

θr	θ0	α	a=1/α	n′
		(kPa)−1	(kPa)
0.0165	0.3014	0.812	1.231	1.703

Physical-volumetric state of the coal in the prototype model during the drying phases

After 7 days of drying at room temperature
w	W (N)	Wd(N)	H (m)	V (m3)	Gs*
17.70%	2096	1781	0.895	0.2238	1.20
γ (kN/m3)	γd (kN/m3)	e	n	Sr	θ
9.37	7.96	0.48	0.32	44.39%	0.144
After 14 days of drying at room temperature
w	W (N)	Wd (N)	H (m)	V (m3)	Gs*
16.73%	2082	1781	0.895	0.2238	1.20
γ (kN/m3)	γd (kN/m3)	e	n	Sr	θ
9.31	7.96	0.48	0.32	41.97%	0.136

Physical-volumetric parameters of the coal in the prototype model: a) at initial state; b) after volumetric collapse

a)
w0	W0 (N)	Wd(N)	H (m)	V (m3)	Gs*
11.21%	1984	1784	1.002	0.2505	1.20
γ (kN/m3)	γd (kN/m3)	e	n	Sr	θ
7.92	7.12	0.65	0.39	20.61%	0.081