Abstract

An understanding of the pore structure features of coral reef limestone is crucial for studying its distinctive macroscopic qualities, because the pore structure greatly influences its mechanical properties and seepage characteristics. In this study, a comprehensive characterization analysis of the pore structures of two types of coral reef limestone samples from the South China Sea was conducted using a combination of polarizing microscopy and computed tomography scanning technology. A watershed segmentation algorithm, based on extended-minima transformation markers, was used to segment the pore structure of coral reef limestone, and quantitative analysis of the characteristic pore parameters was performed. In addition, the relationship between the pore orientation and coral growth structure was investigated. The results indicate that the watershed segmentation algorithm using extended-minima transformation markers can effectively reduce oversegmentation and accurately segment the pore structure of coral reef limestone. Both types of coral reef limestone samples exhibited high porosity and complex pore shapes with significant differences in pore size. The pore equivalent radius follows a normal distribution, and the fractal dimension ranges from 1.58 to 1.75, indicating high fractal and self-similar characteristics. The pore structures of both types of coral reef limestone showed a clear directionality with a regular pattern in pore arrangement, primarily influenced by growth lines. This study has implications for revealing the pore structure characteristics of coral reef limestone and establishing correlations between the macroscopic and microscopic properties.

References

1.
Zhong
Y.
,
Wang
R.
,
Li
Q.
,
Ding
J.
,
Wei
H.
, and
Li
X.
,
“Physical and Engineering Characteristics of Reef Limestone: A Review
” (in Chinese),
Science & Technology Review
38
, no. 
20
(October
2020
):
57
70
, https://doi.org/10.3981/j.issn.1000-7857.2020.20.012
2.
Ma
L.
,
Wu
J.
,
Wang
M.
,
Dong
L.
, and
Wei
H.
, “
Dynamic Compressive Properties of Dry and Saturated Coral Rocks at High Strain Rates
,”
Engineering Geology
272
(
2020
): 105615, https://doi.org/10.1016/j.enggeo.2020.105615
3.
Xu
L.-J.
,
Wang
X.-Z.
,
Wang
R.
,
Zhu
C.-Q.
, and
Liu
X.-P.
, “
Physical and Mechanical Properties of Calcareous Soils: A Review
,”
Marine Georesources and Geotechnology
40
, no. 
6
(June
2022
):
751
766
, https://doi.org/10.1080/1064119X.2021.1927270
4.
Wang
X.
,
Wang
R.
,
Meng
Q.
, and
Chen
J.
, “
Research on Characteristics of Coral Reef Calcareous Rock in Nansha Islands
” (in Chinese),
Chinese Journal of Rock Mechanics and Engineering
27
, no. 
11
(November
2008
):
2221
2226
.
5.
Zheng
K.
,
Meng
Q.
,
Wang
R.
,
Jin
Y.
,
Wu
W.
, and
Yu
K.
, “
Advances in Study of Engineering Geological Characteristics of Coral Reef Limestone
” (in Chinese),
Marine Geology and Quaternary Geology
40
, no. 
1
(February
2020
):
42
49
, https://doi.org/10.16562/j.cnki.0256-1492.2018110601
6.
Huang
J.
,
Li
J.
,
Li
M.
,
Pan
Y.
, and
Zong
Z.
, “
Dynamic Response and Failure Mechanism of Ocean Coral Reef Limestone under High Strain Rate Loading
,”
Ocean Engineering
299
(
2024
): 117370, https://doi.org/10.1016/j.oceaneng.2024.117370
7.
Chang-qi
Z.
,
Hai-feng
L.
, and
Bin
Z.
, “
Micro-structures and the Basic Engineering Properties of Beach Calcarenites in South China Sea
,”
Ocean Engineering
114
(
2016
):
224
235
, https://doi.org/10.1016/j.oceaneng.2016.01.009
8.
Ma
L.
,
Liu
H.
,
Zhang
W.
,
Li
Q.
,
Zhu
H.
, and
Wu
J.
, “
Macroscopic and Mesoscopic Investigation on the Physical and Mechanical Characteristics of Coral Limestone at Different Depths
” (in Chinese),
Geological Journal of China Universities
29
, no. 
3
(June
2023
):
471
478
, https://doi.org/10.16108/j.issn1006-7493.2021074
9.
Tang
G.
and
Zheng
J.
, “
Engineering Properties of Reef Calcareous Rock in Southeast Asia
” (in Chinese),
Geotechnical Investigation & Surveying
43
, no. 
6
(June
2015
):
6
10
.
10.
Wan
Z.
,
Dai
G.
, and
Gong
W.
, “
Full-Scale Load Testing of Two Large-Diameter Drilled Shafts in Coral-Reef Limestone Formations
,”
Bulletin of Engineering Geology and the Environment
77
, no. 
3
(August
2018
):
1127
1143
, https://doi.org/10.1007/s10064-017-1206-1
11.
Liu
T.
,
Shao
Y.
,
Zhang
C.
,
Li
X.
,
Luo
Y.
, and
Wei
X.
, “
Analysis of Crack Propagation and Hydraulic Fracturing Behavior of Coral Reef Limestone
,”
Computational Particle Mechanics.
Published ahead of print, May 6,
2024
, https://doi.org/10.1007/s40571-024-00759-2
12.
Zhang
Y.
,
Liu
W.
,
Liu
Y.
,
Ding
J.
,
Chen
P.
,
Luo
H.
, and
Yao
X.
, “
Study on Bearing Characteristics of Bored Piles in Coral Reef
,”
Geotechnical and Geological Engineering
42
, no. 
1
(January
2024
):
501
521
, https://doi.org/10.1007/s10706-023-02585-4
13.
Liu
Q.
,
Sun
M.
,
Sun
X.
,
Liu
B.
,
Ostadhassan
M.
,
Huang
W.
,
Chen
X.
, and
Pan
Z.
, “
Pore Network Characterization of Shale Reservoirs through State-of-the-Art X-ray Computed Tomography: A Review
,”
Gas Science and Engineering
113
(
2023
): 204967, https://doi.org/10.1016/j.jgsce.2023.204967
14.
Song
W.
,
Liu
F.
,
Li
Y.
, and
Yang
Y.
, “
Pore Scale Modeling of Fluid Transport in Complex Reservoirs: Multi-scale Digital Rock Construction, Flow Experiments and Simulation Methods
,”
Capillarity
11
, no. 
3
(June
2024
):
81
88
, https://doi.org/10.46690/capi.2024.06.03
15.
Qin
X.
,
Xia
Y.
,
Qiao
J.
,
Chen
J.
,
Zeng
J.
, and
Cai
J.
, “
Modeling of Multiphase Flow in Low Permeability Porous Media: Effect of Wettability and Pore Structure Properties
,”
Journal of Rock Mechanics and Geotechnical Engineering
16
, no. 
4
(April
2024
):
1127
1139
, https://doi.org/10.1016/j.jrmge.2023.06.007
16.
Wang
X.
,
Wen
D.
,
Ding
H.
, and
Shi
Q.
, “
Experimental Study on Damage Behavior of Porous Coral Limestone from the Zhongsha Islands, South China Sea
,”
Rock Mechanics and Rock Engineering
56
, no. 
5
(May
2023
):
3787
3803
, https://doi.org/10.1007/s00603-023-03253-y
17.
Wu
K.
,
Meng
Q.
,
Wang
C.
,
Qin
Q.
, and
Dong
Z.
, “
Investigation of Damage Characteristics of Coral Reef Limestone under Uniaxial Compression Based on Pore Structure
,”
Engineering Geology
313
(
2023
): 106976, https://doi.org/10.1016/j.enggeo.2022.106976
18.
Wu
K.
,
Meng
Q.
,
Wang
C.
,
Qin
Q.
, and
Li
C.
, “
Experimental Investigation of Damage Evolution Characteristics of Coral Reef Limestone Based on Acoustic Emission and Digital Volume Correlation Techniques
,”
Rock Mechanics and Rock Engineering
56
, no. 
3
(March
2023
):
2357
2374
, https://doi.org/10.1007/s00603-022-03186-y
19.
Wu
K.
,
Meng
Q.
,
Qin
Q.
,
Jiang
X.
, and
Wang
C.
, “
Microscopic Mechanisms of Coral Reef Limestone Crack Propagation
,”
Marine Georesources and Geotechnology
41
, no. 
12
(December
2023
):
1379
1392
, https://doi.org/10.1080/1064119X.2022.2143305
20.
Li
L.
,
Li
C.
,
Huang
B.
,
Li
J.
,
Li
S.
, and
Li
X.
, “
Meso-mechanical Anisotropy and Fracture Evolution of Reef Limestones from the Maldives Islands and the South China Sea
,”
Journal of Rock Mechanics and Geotechnical Engineering
15
, no. 
12
(December
2023
):
3173
3187
, https://doi.org/10.1016/j.jrmge.2023.02.027
21.
Zhang
H.
,
Ren
H.
,
Mu
C.
,
Wu
X.
,
Huang
K.
,
Zhang
H.
, and
Wang
F.
, “
Experimental Study on Dynamic Mechanical Properties and Damage Characteristics of Coral Reef Limestone
,”
Construction and Building Materials
384
(
2023
): 131007, https://doi.org/10.1016/j.conbuildmat.2023.131007
22.
Wang
J.
,
Huang
X.
,
Xu
J.
,
Zhang
Z.
,
Wang
S.
, and
Li
Y.
, “
Network Analysis of Pore Structure of Coral Reef Limestone and Its Implications for Seepage Flow
,”
Engineering Geology
318
(
2023
): 107103, https://doi.org/10.1016/j.enggeo.2023.107103
23.
Wang
J.
,
Huang
X.
,
Xu
J.
,
Wang
S.
,
Jin
G.
, and
Zhang
Z.
, “
Identifying the Pore Structure and Permeability Anisotropy of Coral Reef Limestone Based on CT Image Analysis
,”
Marine Georesources and Geotechnology
42
, no. 
8
(August
2024
):
993
1010
, https://doi.org/10.1080/1064119X.2023.2243270
24.
Luo
Y.
,
Zhang
M.
,
Gong
H.
,
Jing
W.
, and
Li
X.
, “
Microscopic Pore Structural Characteristics and Grout Diffusion Law of Coral Reef Limestone
,”
Marine Geophysical Researches
44
, no. 
2
(June
2023
): 14, https://doi.org/10.1007/s11001-023-09521-4
25.
Wu
J.
,
Liu
G.
,
Han
X.
,
Zhao
Y.
,
Wei
H.
, and
Yang
J.
,
“Diagenesis of Coral Reefs: An In-Situ Geochemical Study of Coral Reefs at the Yongxing Island, South China Sea
” (in Chinese),
Marine Geology Frontiers
37
, no. 
1
(January
2023
):
31
44
, https://doi.org/10.16028/j.1009-2722.2020.006
26.
Xu
J.
,
Huang
X.
,
Zhang
Z.
, and
Jin
G.
, “
Pore Structure Characteristics of Coral Reef Limestone: A Combined Polarizing Microscope and CT Scanning Study
,” in
Geo Shanghai International Conference 2024 - Volume 3: Transportation Geotechnics
(
Bristol, UK
:
IOP Science
,
2024
), https://doi.org/10.1088/1755-1315/1332/1/012026
27.
Meyer
F.
, “
Topographic Distance and Watershed Lines
,”
Signal Processing
38
, no. 
1
(July
1994
):
113
125
, https://doi.org/10.1016/0165-1684(94)90060-4
28.
Rabbani
A.
,
Jamshidi
S.
, and
Salehi
S.
, “
An Automated Simple Algorithm for Realistic Pore Network Extraction from Micro-tomography Images
,”
Journal of Petroleum Science Engineering
123
(
2014
):
164
171
, https://doi.org/10.1016/j.petrol.2014.08.020
29.
Rabbani
A.
,
Ayatollahi
S.
,
Kharrat
R.
, and
Dashti
N.
, “
Estimation of 3-D Pore Network Coordination Number of Rocks from Watershed Segmentation of a Single 2-D Image
,”
Advances in Water Resources
94
(
2016
):
264
277
, https://doi.org/10.1016/j.advwatres.2016.05.020
30.
Soille
P.
, “
Hit-or-Miss and Skeletons
,” in
Morphological Image Analysis: Principles and Applications
(
New York
:
Springer
,
2002
),
139
182
, https://doi.org/10.1007/978-3-662-05088-0_5
31.
Liu
H.
,
Ma
C.
, and
Zhu
C.
, “
X-ray Micro CT Based Characterization of Pore-Throat Network for Marine Carbonates from South China Sea
,”
Applied Sciences
12
, no. 
5
(March
2022
): 2611, https://doi.org/10.3390/app12052611
32.
Wan
H.
,
Huang
X.
,
Wang
J.
, and
Zhang
Z.
, “
Importance of Appropriate Segmentation in Pore Structure Analysis of Coral Reef Limestone from CT Images
,”
Marine Georesources and Geotechnology
42
, no. 
4
(April
2024
):
327
347
, https://doi.org/10.1080/1064119X.2023.2185170
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