Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (84)

Search Parameters:
Keywords = pore pressure build up

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
24 pages, 11697 KiB  
Article
Layered Production Allocation Method for Dual-Gas Co-Production Wells
by Guangai Wu, Zhun Li, Yanfeng Cao, Jifei Yu, Guoqing Han and Zhisheng Xing
Energies 2025, 18(15), 4039; https://doi.org/10.3390/en18154039 - 29 Jul 2025
Viewed by 178
Abstract
The synergistic development of low-permeability reservoirs such as deep coalbed methane (CBM) and tight gas has emerged as a key technology to reduce development costs, enhance single-well productivity, and improve gas recovery. However, due to fundamental differences between coal seams and tight sandstones [...] Read more.
The synergistic development of low-permeability reservoirs such as deep coalbed methane (CBM) and tight gas has emerged as a key technology to reduce development costs, enhance single-well productivity, and improve gas recovery. However, due to fundamental differences between coal seams and tight sandstones in their pore structure, permeability, water saturation, and pressure sensitivity, significant variations exist in their flow capacities and fluid production behaviors. To address the challenges of production allocation and main reservoir identification in the co-development of CBM and tight gas within deep gas-bearing basins, this study employs the transient multiphase flow simulation software OLGA to construct a representative dual-gas co-production well model. The regulatory mechanisms of the gas–liquid distribution, deliquification efficiency, and interlayer interference under two typical vertical stacking relationships—“coal over sand” and “sand over coal”—are systematically analyzed with respect to different tubing setting depths. A high-precision dynamic production allocation method is proposed, which couples the wellbore structure with real-time monitoring parameters. The results demonstrate that positioning the tubing near the bottom of both reservoirs significantly enhances the deliquification efficiency and bottomhole pressure differential, reduces the liquid holdup in the wellbore, and improves the synergistic productivity of the dual-reservoirs, achieving optimal drainage and production performance. Building upon this, a physically constrained model integrating real-time monitoring data—such as the gas and liquid production from tubing and casing, wellhead pressures, and other parameters—is established. Specifically, the model is built upon fundamental physical constraints, including mass conservation and the pressure equilibrium, to logically model the flow paths and phase distribution behaviors of the gas–liquid two-phase flow. This enables the accurate derivation of the respective contributions of each reservoir interval and dynamic production allocation without the need for downhole logging. Validation results show that the proposed method reliably reconstructs reservoir contribution rates under various operational conditions and wellbore configurations. Through a comparison of calculated and simulated results, the maximum relative error occurs during abrupt changes in the production capacity, approximately 6.37%, while for most time periods, the error remains within 1%, with an average error of 0.49% throughout the process. These results substantially improve the timeliness and accuracy of the reservoir identification. This study offers a novel approach for the co-optimization of complex multi-reservoir gas fields, enriching the theoretical framework of dual-gas co-production and providing technically adaptive solutions and engineering guidance for multilayer unconventional gas exploitation. Full article
Show Figures

Figure 1

18 pages, 2759 KiB  
Article
Microstructural Characteristics of Earth Materials and the Induced Latent Heat on Indoor Environment
by Shenwei Yu, Jun Mu and Zhipeng Liang
Sustainability 2025, 17(13), 5731; https://doi.org/10.3390/su17135731 - 21 Jun 2025
Viewed by 500
Abstract
Earth materials in construction demonstrate significant potential attributed to their accessibility, recyclability, and low energy demands for processing. Modern techniques have enhanced their mechanical strength and durability, enabling their application in load-bearing and infill walls while preserving ecological benefits. However, existing studies on [...] Read more.
Earth materials in construction demonstrate significant potential attributed to their accessibility, recyclability, and low energy demands for processing. Modern techniques have enhanced their mechanical strength and durability, enabling their application in load-bearing and infill walls while preserving ecological benefits. However, existing studies on indoor heat–humidity regulation primarily emphasize material parameters and macro-level performance. Moreover, the dynamic interactions between the unique thermal storage–release mechanisms and indoor environments have not been systematically analyzed. With the Kelvin equation, capillary mechanics, adsorption theories, and microstructural analysis were integrated in this study to quantify cyclic capillary condensation and evaporation in microvoids. The results reveal that earth materials contain abundant medium-sized pores (19.85–53.83 nm) sustaining vapor exchange with their surroundings. Capillary condensation occurs 0.86–0.96 times the planar surface vapor pressure, influenced by pore size (negatively correlated) and temperature (negatively correlated). During the daytime, capillary evaporation occurs in the nanopores of the raw earth wall under the influence of the outdoor environment’s cyclical temperature and humidity. This process absorbs heat from the indoor environment and raises the ambient humidity. During the nighttime, capillary condensation occurs in the pores, releasing heat to the indoor area and absorbing moisture from the environment, contributing to the balance of the indoor thermal environment of the earth buildings. The findings lay a scientific foundation for quantitatively evaluating earth buildings’ indoor climate control performance, supporting their integration into green building systems. This research bridges knowledge gaps in micro-to-macro thermal dynamics while advancing the ecological optimization of materials for sustainable architecture. Full article
Show Figures

Figure 1

14 pages, 3844 KiB  
Article
Ambient-Dried Silica Xerogels with Enhanced Strength and Thermal Insulation via Calcium Ion-Glycerol Synergistic Crosslinking
by Xiaoyu Xie, Zilin Zhu, Yu Meng, Lijia Wang, Fuquan Zhao, Lingqing Chen, Lijie Jiang, Ming Yan and Xiaofan Zhou
Gels 2025, 11(6), 462; https://doi.org/10.3390/gels11060462 - 16 Jun 2025
Viewed by 460
Abstract
Despite their high porosity and wide applicability, silica xerogels face mechanical strength limitations for high-performance applications. This study presents an ambient-pressure sol-gel strategy utilizing calcium-glycerol synergy to produce robust xerogels with enhanced properties. Physicochemical analyses reveal that controlled Ca2+ incorporation (optimal at [...] Read more.
Despite their high porosity and wide applicability, silica xerogels face mechanical strength limitations for high-performance applications. This study presents an ambient-pressure sol-gel strategy utilizing calcium-glycerol synergy to produce robust xerogels with enhanced properties. Physicochemical analyses reveal that controlled Ca2+ incorporation (optimal at 6 wt.%) accelerates gelation kinetics while establishing a hybrid network through ionic complexation and hydrogen bonding. The resulting xerogels achieve exceptional compressive strength (30.8 MPa) while maintaining uniform mesoporosity (50–90 nm pore size). Remarkably, the as-prepared silica xerogels demonstrate outstanding thermal insulation, maintaining a 220 °C temperature differential in 300 °C environments. These results prove that the ambient-pressure sol-gel strategy utilizing calcium-glycerol synergy can enhance the mechanical performance and thermal insulation performance of silica xerogels with the dual actions of Ca2+-induced network reinforcement via silanol coordination and glycerol-mediated stress relief during ambient drying. Overall, this work can offer a scalable, energy-efficient approach to produce high-performance silica xerogels with huge potential in building envelopes and aerospace systems. Full article
(This article belongs to the Special Issue Silica Aerogel: Synthesis, Properties and Characterization)
Show Figures

Figure 1

19 pages, 8223 KiB  
Article
Model Test of Mechanical Response of Negative Poisson’s Ratio Anchor Cable in Rainfall-Induced Landslides
by Guangcheng Shi, Zhigang Tao, Feifei Zhao, Jie Dong, Xiaojie Yang, Zhouchao Xu and Xiaochuan Hu
Buildings 2025, 15(10), 1745; https://doi.org/10.3390/buildings15101745 - 21 May 2025
Viewed by 509
Abstract
Rainfall-induced landslide mitigation remains a critical research focus in geotechnical engineering, particularly for safeguarding buildings and infrastructure in unstable terrain. This study investigates the stabilizing performance of slopes reinforced with negative Poisson’s ratio (NPR) anchor cables under rainfall conditions through physical model tests. [...] Read more.
Rainfall-induced landslide mitigation remains a critical research focus in geotechnical engineering, particularly for safeguarding buildings and infrastructure in unstable terrain. This study investigates the stabilizing performance of slopes reinforced with negative Poisson’s ratio (NPR) anchor cables under rainfall conditions through physical model tests. A scaled geological model of a heavily weathered rock slope is constructed using similarity-based materials, building a comprehensive experimental setup that integrates an artificial rainfall simulation system, a model-scale NPR anchor cable reinforcement system, and a multi-parameter data monitoring system. Real-time measurements of NPR anchor cable axial forces and slope internal stresses were obtained during simulated rainfall events. The experimental results reveal distinct response times and force distributions between upper and lower NPR anchor cables in reaction to rainfall-induced slope deformation, reflecting the temporal and spatial evolution of the slope’s internal sliding surface—including its generation, expansion, and full penetration. Monitoring data on volumetric water content, earth pressure, and pore water pressure within the slope further elucidate the evolution of effective stress in the rock–soil mass under saturation. Comparative analysis of NPR cable forces and effective stress trends demonstrates that NPR anchor cables provide adaptive stress compensation, dynamically counteracting internal stress redistribution in the slope. In addition, the structural characteristics of NPR anchor cables can effectively absorb the energy released by landslides, mitigating large deformations that could endanger adjacent buildings. These findings highlight the potential of NPR anchor cables as an innovative reinforcement strategy for rainfall-triggered landslide prevention, offering practical solutions for slope stabilization near buildings and enhancing the resilience of building-related infrastructure. Full article
Show Figures

Figure 1

16 pages, 11809 KiB  
Article
Multi-Layer Filter Material with a Superoleophobic Pore Size Gradient for the Coalescence Separation of Surfactant-Stabilized Oil-in-Water Emulsions
by Xingdong Wu, Ying Wang, Chengzhi Li, Lang Liu, Xiaowei Li and Cheng Chang
Processes 2025, 13(5), 1600; https://doi.org/10.3390/pr13051600 - 21 May 2025
Viewed by 517
Abstract
The performance of oil–water coalescence separation elements currently fails to meet the increasing demands of the oily wastewater treatment industry. To address this challenge, a series of fiber coalescing filters were developed through an underwater superoleophobic modification process using a simple impregnation technique. [...] Read more.
The performance of oil–water coalescence separation elements currently fails to meet the increasing demands of the oily wastewater treatment industry. To address this challenge, a series of fiber coalescing filters were developed through an underwater superoleophobic modification process using a simple impregnation technique. The effect of varying surface wettability on the separation efficiency of oil-in-water (O/W) emulsions stabilized with surfactants was investigated. The results demonstrate that, after undergoing underwater superoleophobic modification, the separation efficiency of the fiber filter material improved by 33.9%, the pressure drop was reduced by 46.1%, and the steady-state quality factor increased by 83.3%. Building upon these findings, an oil-repellent pore size gradient structure was introduced for the coalescence separation of surfactant-stabilized oil-in-water emulsions. This structure exhibited outstanding characteristics, including a low pressure drop and a high-quality factor. Furthermore, when processing emulsions stabilized with surfactants such as OP-10 (nonionic), CTAB (cationic), and SDS (anionic), the structure maintained high separation efficiencies of 93.6%, 96.4%, and 97.2%, respectively, after 10 cycles. Finally, based on experimental data and theoretical analysis, a separation mechanism for oil–water coalescence using superoleophobic pore size gradient filtration materials is proposed. This structure demonstrates significant potential for widespread application in liquid–liquid separation technologies. Full article
(This article belongs to the Special Issue Multiphase Flow Process and Separation Technology)
Show Figures

Figure 1

15 pages, 7855 KiB  
Article
Fabrication of Sustainable Diatomite-Based Foams with a Micro-Macroporous Synergistic Structure
by Hailong Ning, Zhiwu Li, Ning Liu, Chengling Li, Yao Lu and Long Li
Materials 2025, 18(9), 1968; https://doi.org/10.3390/ma18091968 - 26 Apr 2025
Viewed by 452
Abstract
This study developed a foamed material with a synergistic microporous-macroporous structure through chemical foaming and high-pressure curing to better utilize the microporous properties of diatomaceous earth in building materials. The effects of different amounts of foaming agent, foam stabilizer, and CaO/SiO2 on [...] Read more.
This study developed a foamed material with a synergistic microporous-macroporous structure through chemical foaming and high-pressure curing to better utilize the microporous properties of diatomaceous earth in building materials. The effects of different amounts of foaming agent, foam stabilizer, and CaO/SiO2 on the mechanical properties and pore structure of the samples were investigated. The experimental results demonstrate that, under the influence of the foaming agent, the foam material has developed a multi-stage pore structure that integrates both macropores and micropores. This unique structure results in a dry density range of 467–670 kg/m3, thereby achieving significant material lightweighting. In addition, these macropores enhance the interaction between the micropores of diatomaceous earth and the external environment interface, thereby achieving a balance between the material’s structural stability and functional properties. The material exhibits a porosity of 76.9% and a specific surface area of 42.9 m2/g, while maintaining a high compressive strength of 2.67 MPa. This work provides a technological pathway for the fabrication of multifunctional building materials that have both lightweight and eco-functional properties. Full article
(This article belongs to the Section Construction and Building Materials)
Show Figures

Graphical abstract

13 pages, 2333 KiB  
Article
Deformation Study of Strongly Structured Clays Considering Damage Effects
by Yansong Shi, Bin Tang, Yinchuan Wang and Yanhua Xie
Appl. Sci. 2025, 15(6), 2969; https://doi.org/10.3390/app15062969 - 10 Mar 2025
Viewed by 531
Abstract
Settlement values calculated per the current “Code for Design of Building Foundations” demonstrate significant discrepancies when compared to the actual measured settlement values observed after disturbing a strong, cohesive soil foundation. This inconsistency introduces uncertainties in engineering design. To investigate the deformation behavior [...] Read more.
Settlement values calculated per the current “Code for Design of Building Foundations” demonstrate significant discrepancies when compared to the actual measured settlement values observed after disturbing a strong, cohesive soil foundation. This inconsistency introduces uncertainties in engineering design. To investigate the deformation behavior of highly structured clay, which is particularly sensitive to disturbances, this study employed a shaking table to subject undisturbed soil samples to various disturbance levels. The shaking frequencies were set at 20 Hz, 35 Hz, and 50 Hz, with durations of 30, 60, 90, and 120 min. One-dimensional compression tests were performed to examine the relationship between soil deformation parameters and overburden pressure, alongside an analysis of the deformation process and pore structure damage in the highly structured clay. A fitting process using Origin software was utilized to develop a deformation modulus calculation model that accounted for disturbance and damage effects, aiming to enhance the accuracy of foundation settlement predictions. The results indicate that the proposed empirical formula for the deformation modulus is highly reliable, which is essential for improving the precision of foundation settlement calculations and ensuring engineering safety. Full article
Show Figures

Figure 1

21 pages, 5507 KiB  
Article
Load-Bearing Performance of Precast Piles with Integrated Side Drainage Channels in Coastal Soft Soil
by Shu-Hao Hu, Yue-Bao Deng, Shan Yu and Ri-Hong Zhang
Sustainability 2025, 17(5), 2324; https://doi.org/10.3390/su17052324 - 6 Mar 2025
Cited by 1 | Viewed by 697
Abstract
To accelerate the dissipation of excess pore water pressure, enhance the bearing capacity of piles, and mitigate long-term settlement in soft ground, a novel green and lowcarbon pile foundation technology, termed the precast drainage pile (PDP) technology, is proposed. This innovative approach integrated [...] Read more.
To accelerate the dissipation of excess pore water pressure, enhance the bearing capacity of piles, and mitigate long-term settlement in soft ground, a novel green and lowcarbon pile foundation technology, termed the precast drainage pile (PDP) technology, is proposed. This innovative approach integrated precast pipe piles with prefabricated vertical drains (PVDs) attached to their sides. The piles were installed using static pile pressing and were subsequently subjected to vacuum-induced negative pressure to facilitate soil consolidation, which enhances the resource utilization rate of pile foundations and promotes the sustainable utilization of soft soil foundations. To investigate the bearing characteristics of the PDP, this study combined the shear displacement method for piles with the consolidation theory of soft soil foundations. A calculation model for the load-settlement behavior of precast piles, accounting for the influence of vacuum-induced soil consolidation, was derived, establishing a method for analyzing the load transfer mechanism of PDPs. The reliability of the theoretical model was validated through comparisons with engineering test results. Building on this foundation, the influence of factors such as consolidation period and pile length on the bearing characteristics of PDPs was analyzed. The results demonstrated that, compared to a 10 m precast pile without drainage, the ultimate bearing capacity of single piles with drainage durations of 3, 7, 14, and 28 days increased by 7.3%, 12.7%, 20.3%, and 29.6%, respectively. Furthermore, under a 7-day drainage condition, the bearing capacity of piles with lengths of 10 m, 20 m, and 30 m increased by 12.7%, 12.8%, and 13.1%, respectively. Overall, the findings of this study provide a theoretical basis for the research, development, and design calculations of this new sustainable pile technology. Full article
Show Figures

Figure 1

26 pages, 4655 KiB  
Article
Mechanistic Modelling for Optimising LTES-Enhanced Composites for Construction Applications
by Chrysa Politi, Antonis Peppas, Maria Taxiarchou and Irene Koronaki
Buildings 2025, 15(3), 351; https://doi.org/10.3390/buildings15030351 - 23 Jan 2025
Cited by 1 | Viewed by 837
Abstract
This study addresses the optimisation of latent heat thermal energy storage (LTES) composites for construction applications by utilising mechanistic modelling. The work focuses on enhancing the performance of phase change materials (PCMs) incorporated into expanded perlite (EP) for building energy efficiency by delivering [...] Read more.
This study addresses the optimisation of latent heat thermal energy storage (LTES) composites for construction applications by utilising mechanistic modelling. The work focuses on enhancing the performance of phase change materials (PCMs) incorporated into expanded perlite (EP) for building energy efficiency by delivering sorption capacity models analysing factors such as particle size, surface area, and pore volume, particularly highlighting the performance of EP as a PCM carrier due to its high porosity (around 90%) and large surface area (up to 20 m2/g), which allowed for improved energy storage density and heat transfer. Key challenges in the integration of PCMs into construction materials, such as limited thermal conductivity and leakage during phase transitions, are explored. The model evaluates key parameters affecting sorption, such as temperature, pressure, and surface characteristics of the materials. The results indicate that while higher temperatures enhance sorption in larger pores, they reduce efficiency in smaller ones, leading to a slight overall decrease in total sorption capacity at elevated temperatures. The sorption capacity of water is a value slightly above 2 kg/kg EP, while the PCM RT27 exhibits a sorption capacity of 0.59 kg/kg EP. These results represent the optimised sorption performance in terms of temperature between 40 °C and 50 °C. Furthermore, applying vacuum impregnation is investigated in relation to the pore radii of the EP particles. Larger pore radii show a noticeable improvement in overall sorption capacity from 0.59 kg/kg EP to 0.68 kg/kg EP as pressure increases, especially beyond 4 × 105 Pa. The contribution of inter-particle sorption remains stable, while the intra-particle sorption in large pores drives the overall capacity upward. The findings convey significant findings in optimising the design of LTES-enhanced composites for improved energy storage, thermal regulation, and structural integrity in building applications. Full article
(This article belongs to the Special Issue Research on Advanced Technologies Applied in Green Buildings)
Show Figures

Figure 1

23 pages, 11798 KiB  
Article
Study on the Influencing Factors of CO2 Storage in Low Porosity-Low Permeability Heterogeneous Saline Aquifer
by Hongchang Hu, Dongdong Wang, Yujie Diao, Chunyuan Zhang and Ting Wang
Processes 2024, 12(12), 2933; https://doi.org/10.3390/pr12122933 - 22 Dec 2024
Viewed by 917
Abstract
The safety and long-term storage capacity of CO2 geological storage are necessary factors for project design and engineering development. Evaluating the influencing factors of CO2 storage and quantitatively analyzing the sensitivity of each parameter have an important guiding role in the [...] Read more.
The safety and long-term storage capacity of CO2 geological storage are necessary factors for project design and engineering development. Evaluating the influencing factors of CO2 storage and quantitatively analyzing the sensitivity of each parameter have an important guiding role in the design and development of storage projects. In this paper, the Liujiagou Formation in the northeast of the Ordos Basin is taken as an example. Based on the TOUGH/Petrasim simulation tool, the RZ2D geological storage model is established. Seven influencing factors, namely salinity, temperature, horizontal and vertical permeability ratio, pore geometry factor, residual gas saturation, liquid saturation and pore compression coefficient, were compared and analyzed to control the plume migration behavior, interlayer pressure accumulation and storage capacity of low porosity and low permeability heterogeneous reservoirs, and the sensitivity of each parameter to interlayer pressure and storage capacity was quantitatively analyzed. The simulation results show that the uncertain factors affect the safety of CO2 geological storage to a certain extent by affecting the speed of the residual storage and dissolution storage mechanism. High residual gas saturation and salinity will make CO2 mostly exist in the form of free state, which will adversely affect the safety and storage capacity of CO2 saline aquifer storage. High temperature and high vertical permeability ratio will lead to higher interlayer pressure accumulation, which is not conducive to the safety of the storage project but is beneficial to the storage capacity. Temperature, transverse and longitudinal permeability ratio and pore geometry factor control the propagation velocity of plume. The larger these factors are, the faster the plume velocity is. Higher liquid phase saturation is not better; higher liquid phase saturation leads to a large build-up of pressure in the reservoir and can have an adverse effect on the storage volume. The sensitivity analysis of all factors shows that the liquid saturation and temperature have the greatest influence on CO2 geological storage, and the pore compression coefficient has the least influence. The conclusions of this paper can provide a theoretical reference for the design and development of a CO2 saline aquifer storage project in a low porosity and low permeability reservoir area. Full article
Show Figures

Figure 1

14 pages, 8788 KiB  
Article
Influence of a Frame Structure Building Demolition on an Adjacent Subway Tunnel: Monitoring and Analysis
by Wei Wang, Xianqi Xie, Fang Yuan, Peng Luo, Yue Wu, Changbang Liu and Senlin Nie
Buildings 2024, 14(12), 3974; https://doi.org/10.3390/buildings14123974 - 14 Dec 2024
Viewed by 943
Abstract
In a complex urban environment, the impact of building demolitions by blasting on the structural integrity of nearby metro tunnels is critical. This study systematically analyzed the blasting and demolition process of a building adjacent to a metro tunnel using various monitoring methods, [...] Read more.
In a complex urban environment, the impact of building demolitions by blasting on the structural integrity of nearby metro tunnels is critical. This study systematically analyzed the blasting and demolition process of a building adjacent to a metro tunnel using various monitoring methods, including blasting vibration, dynamic strain, deformation and settlement, pore water pressure, and displacement. The results indicate that the metro tunnel’s vibration response can be divided into four stages: notch blasting, notch closure, overall collapse impact, and auxiliary notch blasting. The most significant impact on the tunnel segments occurred during the building’s ground impact phase, with a peak particle velocity of 0.57 cm/s. The maximum tensile and compressive stresses induced in the tunnel segments did not exceed 0.4 MPa, well within the safety limits. Displacement and settlement changes in the tunnel structure were less than 1 mm, far below the warning threshold. Additionally, blasting vibrations significantly affected the pore water pressure in the surrounding soil. However, fluctuations caused by ground impact vibrations were minimal, and the pore water pressure quickly returned to its initial level after the blasting concluded. Throughout the process, no adverse effects on the metro tunnel structure were observed. Full article
(This article belongs to the Section Building Structures)
Show Figures

Figure 1

15 pages, 12983 KiB  
Article
Study on the Macro-/Micrometric Characteristics and Mechanical Properties of Clayey Sandy Dredged Fill in the Guangdong Area
by Qiunan Chen, Xiaodi Xu, Ao Zeng, Yunyang Yan, Yan Feng, Kun Long and Chenna Qi
Materials 2024, 17(23), 6018; https://doi.org/10.3390/ma17236018 - 9 Dec 2024
Cited by 1 | Viewed by 720
Abstract
The study of dredged fill in Guangdong (GD), China, is of great significance for reclamation projects. Currently, there are relatively few studies on dredged fill in Guangdong, and there are many differences in the engineering characteristics of dredged fill foundations formed through land [...] Read more.
The study of dredged fill in Guangdong (GD), China, is of great significance for reclamation projects. Currently, there are relatively few studies on dredged fill in Guangdong, and there are many differences in the engineering characteristics of dredged fill foundations formed through land reclamation and natural foundations. In order to have a more comprehensive understanding of the physico-mechanical properties of blowing fill in the coastal area of GD and to understand the effect of its long-term creep row on the long-term settlement and deformation of buildings, the material properties, microstructure, elemental composition, triaxial shear properties, and triaxial creep properties of dredged fill in Guangdong were studied and analyzed through indoor geotechnical tests, scanning electron microscopy (SEM), X-ray diffraction (XRD), and conventional triaxial shear tests and triaxial creep tests. The test results showed that the Guangdong dredged fill is characterized by a high water content, high pore ratio, and high-liquid-limit clayey sand, and the mineral composition is dominated by quartz and whitmoreite. The scanning electron microscopy results showed that the particles of the dredged fill showed an agglomerated morphology, and the surface of the test soil samples had scaly fine flakes and a fragmented structure. In the triaxial shear test, the GD dredged fill showed strain hardening characteristics, and the effective stress path showed continuous loading characteristics; the consolidated undrained shear test showed that the GD dredged fill had shear expansion characteristics under low-perimeter-pressure conditions. It was found that, with an increase in bias stress, the axial strain in the consolidated undrained triaxial creep test under the same perimeter pressure conditions gradually exceeded the axial strain in the consolidated drained triaxial creep test. The results of this study are of theoretical and practical significance for further understanding the mechanical properties of silty soils in the region and for the rational selection of soil strength parameters in practical engineering design. Full article
(This article belongs to the Special Issue Rock-Like Material Characterization and Engineering Properties)
Show Figures

Figure 1

18 pages, 8779 KiB  
Case Report
Correlational Research of Strength Parameters of Waste Soils Determined in the Laboratory and In Situ in Cracow
by Jakub Zięba and Elżbieta Pilecka
Appl. Sci. 2024, 14(23), 10783; https://doi.org/10.3390/app142310783 - 21 Nov 2024
Viewed by 1041
Abstract
This work presents an analysis of the relationship between strength parameters determined in the laboratory and the results of a cone penetration test with pore water pressure measurement (CPTU) of waste soils in the “White Seas” area in Cracow. Anthropogenic soil is an [...] Read more.
This work presents an analysis of the relationship between strength parameters determined in the laboratory and the results of a cone penetration test with pore water pressure measurement (CPTU) of waste soils in the “White Seas” area in Cracow. Anthropogenic soil is an alkaline waste formed during the production of soda ash and deposited in the area of the former Solvay Sodium Plant factory in Cracow, Poland. Due to the large area of the land and numerous investment plans and completed buildings, there was a need to identify reliable functional relationships enabling the determination of the strength parameters of these soils based on the results of the CPTU. Statistical analysis showed that the best correlation with the test results was provided by two logarithmic functions in which the dependent variables were the effective friction angle and effective cohesion. The dependent variable for both cases was the corrected cone resistance qt. The functional relationship combined data from labour-intensive, long-lasting and costly laboratory measurements with quick and less expensive measurements, i.e., in situ CPTUs. The obtained relationships enable the determination of the strength properties of the subsoil of these anthropogenic soils. Full article
(This article belongs to the Section Civil Engineering)
Show Figures

Figure 1

13 pages, 7177 KiB  
Article
Preparation of an FA-Based Discoloration Material and Its Application in Jewelry Design
by Xiaomin Zhang, Xiangrui Gao, Yue Yuan, Guangqin Yang and Yanchen Li
Materials 2024, 17(22), 5628; https://doi.org/10.3390/ma17225628 - 18 Nov 2024
Viewed by 1241
Abstract
Fly ash (FA) is the main solid waste emitted from coal-fired power plants. Due to its high yield, low utilization rate, and occupation of a large amount of land, it exerts enormous pressure on the Earth’s environment. With the deepening of the concept [...] Read more.
Fly ash (FA) is the main solid waste emitted from coal-fired power plants. Due to its high yield, low utilization rate, and occupation of a large amount of land, it exerts enormous pressure on the Earth’s environment. With the deepening of the concept of sustainable development, exploring the reuse of industrial waste such as FA has become a key strategy. If FA can be combined with commonly used jewelry in people’s lives, it will be of great significance to promote the high-net-worth utilization of FA. Therefore, this study synthesized a fly-ash-based composite material with color-changing function and combined it with necklaces as the main material. In the first stage, after blending fly ash and slag, an alkaline activator with a total mass of 10% was added. When the proportion of fly ash was 60%, the compressive strength of the prepared fly-ash-based composite material reached 10.1 MPa. This was attributed to the reaction between sodium silicate in the alkaline activator and free CaO, MgO, and other substances in the fly ash to form hydrated silicate colloids, which solidify the fly ash and transform it into a complex three-dimensional network skeleton. In the second stage, a UV resistant coating with thermochromic function was obtained by blending acrylic resin, TiO2, and a thermosensitive color-changing agent. It was applied to the surface of fly-ash-based composite materials, and the results showed that as the content of the color-changing agent increased, the number of pores on the surface of the coating gradually decreased. When the content of color-changing agent was 10%, the prepared 10%FAB not only had good surface color but also had good thermal stability, UV absorption ability, superhydrophobicity, and mechanical properties. Therefore, 10%FAB was selected as the basic material for jewelry design. In the third stage, the traditional Chinese technique of “gold inlaid with jade” was utilized to develop jewelry applications for the FA composites. As such, 10%FAB was processed into necklaces, which not only had modern design aesthetics but also had good color-changing effects above 30 °C. And after a long period of UV aging experiments, the necklace did not show any wrinkles, bubbles, or other phenomena. Due to the excitation of TiO2 hole–electron pairs, the necklace’s UV absorption ability was further improved. This study demonstrates the potential application of industrial waste in decorative products, expands the high-end utilization of fly ash as a low-cost material, and provides new ideas for building a low-carbon lifestyle. Full article
Show Figures

Figure 1

15 pages, 2843 KiB  
Article
Numerical Simulation of CBM Seepage Characteristics Based on Fracture Network Images
by Wenbin Li, Yongjian Zhu, Yafei Luo, Mingxing Wei and Xizhi Wang
Processes 2024, 12(11), 2381; https://doi.org/10.3390/pr12112381 - 29 Oct 2024
Viewed by 1094
Abstract
The natural fracture network within the coal body serves as the main pathway for gas migration, with its geometric characteristics significantly impacting coalbed methane flow. In order to enhance the numerical model for simulating coalbed methane flow based on fracture network images, we [...] Read more.
The natural fracture network within the coal body serves as the main pathway for gas migration, with its geometric characteristics significantly impacting coalbed methane flow. In order to enhance the numerical model for simulating coalbed methane flow based on fracture network images, we define porosity and permeability functions for these images and improve upon existing methods. By employing a pixel probability decomposition algorithm, we establish a geometric model of a rough discrete fracture network, which is imported into COMSOL Multiphysics to build a numerical model of gas flow. We analyze the impact of different fracture structures on coal seam permeability and find that gas primarily flows through interconnected fractures at much higher velocities compared to matrix pores. Furthermore, we observe that fracture network permeability increases with increasing porosity (0.0635–0.164), fractal dimension (1.571–1.755), maximum fracture branch length (0.0111–0.0249 m), and connectivity (0.808–2.789). Conversely, it decreases with an increasing fracture dip angle (1.61–88.39°) and tortuosity fractal dimension (1.0018–1.0195). Our simulation method based on fracture network imaging provides a simple yet feasible approach to simulate gas extraction while accurately capturing various stages in the extraction process, including the temporal and spatial evolution of gas velocity and pressure as well as differences between fractures and the coal matrix. Full article
(This article belongs to the Section Energy Systems)
Show Figures

Figure 1

Back to TopTop