Biogeotechnics最新文献

{"title":"A review of bio-inspired geotechnics-perspectives from geomaterials, geo-components, and drilling & excavation strategies","authors":"Wengang Zhang ,&nbsp;Jiaying Xiang ,&nbsp;Ruijie Huang ,&nbsp;Hanlong Liu","doi":"10.1016/j.bgtech.2023.100025","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100025","url":null,"abstract":"<div><p>As urbanization progresses, the demand for high-rise buildings and underground spaces is growing, and the need for firm geotechnical construction materials, efficient excavation methods, accurate testing instruments, and innovative geotechnical engineering theories and technologies is increasing. By investigating the phenomena of strengthening and toughening in nature, hydrophobic and ice-phobic, friction anisotropy and drilling as well as excavation, etc, researchers have found that organisms have distinctive external morphology and organization. By imitating the external morphology, structural characteristics or movement mechanism of organisms, novel ideas, new principles, and innovative theories can be provided for the innovation and sustainable development of geotechnical engineering. This paper mainly expounds on the bio-inspired application in geotechnical engineering from three perspectives: geo-materials, geotechnical components, and drilling &amp; excavation equipment, and lists typical application cases. In conclusion, this paper presents a summary and prospects of bio-inspired geotechnical engineering, offering fundamental insights for future research.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 3","pages":"Article 100025"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-grouting technologies for enhancing uniformity of biocementation: A review","authors":"Junjie Zheng ,&nbsp;Hanjiang Lai ,&nbsp;Mingjuan Cui ,&nbsp;Xingzhi Ding ,&nbsp;Yajie Weng ,&nbsp;Jianwei Zhang","doi":"10.1016/j.bgtech.2023.100033","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100033","url":null,"abstract":"<div><p>Biocementation-based soil improvement is an emerging ground treatment method in geotechnical engineering that has garnered extensive attention over the past two decades. One of the challenges associated with this method revolves around the uniformity of biocementation, a crucial factor closely tied to bio-grouting technology. The traditional biotreatment methods, the two-phase method and the one-phase method, suffer from the issue of non-uniform biocementation. Consequently, in recent years, various improved grouting technologies have been proposed to address this concern by aiding bacterial adsorption and controlling carbonate precipitation. This paper reviews the mechanisms and grouting processes employed in these enhanced bio-grouting technologies. Additionally, the challenges of implementing these grouting technologies in real-world applications are also thoroughly discussed.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 3","pages":"Article 100033"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of drying-wetting cycles on the durability of calcareous sand reinforced by MICP and recycled shredded coconut coir (RSC)","authors":"Hailei Kou ,&nbsp;Xiang He ,&nbsp;Zhendong Li ,&nbsp;Weiwei Fang ,&nbsp;Xixin Zhang ,&nbsp;Zhaotun An ,&nbsp;Yalei Wu","doi":"10.1016/j.bgtech.2023.100038","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100038","url":null,"abstract":"<div><p>Microbial-induced carbonate precipitation (MICP) technique has been adopted in geotechnical engineering widely. In this study, the effect of drying-wetting cycles on MICP-recycled shredded coconut coir (RSC) reinforced calcareous sand was studied, and the deterioration mechanism under drying-wetting cycles was revealed. Test results indicated that drying-wetting cycles exert an important influence on the durability of MICP-RSC reinforced specimens. With the increase of drying-wetting cycles <em>N</em>, the specimens demonstrated significant increase in mass loss rate and critical void ratio, decrease in maximum shear modulus, peak strength and toughness. Furthermore, an increase in the initial relative density reduced the deterioration of MICP-RSC reinforced specimens exposed to drying-wetting cycles. Higher initial relative density of the specimen correlates with an increased maximum shear modulus, peak stress and toughness, a decreased in permeability and critical void ratio. Microanalysis revealed that the generated calcium carbonate adhering to sand particles and RSC gradually dropped off with the increase of <em>N</em>, weakened cementation, and led to the deterioration of MICP-RSC reinforced specimens, which is consistent with the deterioration characteristics under drying-wetting cycles.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 3","pages":"Article 100038"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49710384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal and mechanical properties of bio-cemented quartz sand mixed with steel slag","authors":"Shuang Li ,&nbsp;Ming Huang ,&nbsp;Mingjuan Cui ,&nbsp;Kai Xu ,&nbsp;Guixiao Jin","doi":"10.1016/j.bgtech.2023.100036","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100036","url":null,"abstract":"<div><p>The aim of this study is to disclose the feasibility of improving the thermal conductivity and mechanical strength of quartz sand steel slag mixtures treated by enzyme-induced carbonate precipitation (EICP). In this work, the effects of steel slag content (<em>SSC</em>) and number of treatment cycle (<em>N</em>) on the thermal conductivity and mechanical strength of EICP-treated specimens were investigated. The immersion method was adopted for specimen preparation. The thermal conductivity was measured by transient plane source method (TPS) and the unconfined compressive strength (UCS) was obtained through a uniaxial compression test. Moreover, the SEM test was conducted to obtain the morphology and deposition characteristics of calcium carbonate crystals. The result shows that the thermal conductivity and UCS of EICP-treated sands increase before decreasing as the <em>SSC</em> increases. Consequently, the maximum values of thermal conductivity and UCS are 1.28 W/(m⊡K) and 6.31 MPa, respectively, corresponding to the optimal parameter of 20% <em>SSC</em> at 12 <em>N</em>. The optimal thermal conductivity and UCS increase by 367% and 137%, respectively, compared to that of EICP-treated sand with no addition of steel slag. The SEM analysis indicates that the spherical calcium carbonate exists in the range of 0–20% <em>SSC</em>, whereas there is mainly amorphous calcium carbonate when the <em>SSC</em> varies from 40% to 80%. It also demonstrates that the UCS is more sensitive to the variation of calcium carbonate content than that of thermal conductivity.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 3","pages":"Article 100036"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical properties and disintegration behavior of EICP-reinforced sea sand subjected to drying-wetting cycles","authors":"Kai Xu ,&nbsp;Ming Huang ,&nbsp;Zijian Liu ,&nbsp;Mingjuan Cui ,&nbsp;Shuang Li","doi":"10.1016/j.bgtech.2023.100019","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100019","url":null,"abstract":"<div><p>Enzyme-induced carbonate precipitation (EICP) has emerged promising in various geotechnical applications, and has been presented as an alternative to the traditional cementitious materials-based ground improvement method. However, the study on mechanical properties and disintegration behavior of EICP-reinforced sea sand subjected to drying-wetting cycles are limited. This study investigated the mechanical properties and disintegration behavior of EICP-reinforced sea sand against the impact of drying-wetting (D-W) cycles. The uniaxial compressive strength (UCS) tests were performed to discuss the effect of drying-wetting cycles on the mechanical behavior of EICP-treated sea sand. The disintegration tests were conducted on EICP-treated sea sand to investigate the disintegration resistance of bio-cemented samples with various cementation levels. The microstructures of samples before and after disintegration were examined to disclose the disintegration mechanisms of EICP-reinforced sea sand. D-W cycles significantly affect the mechanical properties of EICP-reinforced sea sand, with UCS decreasing by 63.7% after undergoing 15 D-W cycles. The disintegration resistance index of specimens with a lower cementation level decreases significantly under the effect of D-W treatment. The higher disintegration resistance of specimens with higher cementation can be attributed to more crystals with better crystallinity formed in the contact point between sand particles within specimen. The crystals formed by soybean husk urease are mainly calcite and the crystallinity of spherical calcites would gradually change into larger rhombic calcite with further bio-grouting. The crystal with poor crystallinity is susceptible to the effect of D-W treatment, resulting in the obvious disintegration of EICP-reinforced sea sand. Overall, this study is expected to provide useful guidance on the long-term stability and drying-wetting disintegration mechanisms of EICP-reinforced sea sand.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100019"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49731833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of rainfall infiltration in soil slope using a controllable biocementation method","authors":"Xiaohua Pan ,&nbsp;Jian Chu ,&nbsp;Liang Cheng","doi":"10.1016/j.bgtech.2023.100023","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100023","url":null,"abstract":"<div><p>Reasonable control of rainwater infiltration rate can ensure that soil slope will not fail due to rapid infiltration of rainwater in heavy rainfall, and at the same time, more rainwater can be infiltrated in light rainfall to meet the water demand of animals and plants. In this study, based on microbial-induced calcium carbonate precipitation (MICP) technique, a controllable bio-method for rainfall infiltration of soil slope was proposed. To have a comprehensive understanding the relationship among the rainwater infiltration control capacity, biocement treated soil permeability, slope angle and rainfall intensity, a series of physical modelling experiments of rainfall diversion on slopes with three types of soils and three slope angles were carried out in the presence of various rainfall intensities. Experimental results indicated that the proposed bio-method had the ability of controlling rainwater infiltration in term of varying rounds of biocement spraying treatment. In general, it was found that the rainwater infiltration decreases with the increase in slope angle and rainfall intensity. In the worst case of smallest slope angle (15°) and lightest rainfall intensity (n = 50 mm/h), more than 82.6%, 92.2% and 84.4% of rainwater were prevented from infiltration into the MICP treated natural sand, fine sand and medium sand, respectively, while the untreated soils were not able to prevent the rainwater infiltration at all. The corresponding maximum local uniaxial compressive strength for the MICP treated natural sand, fine sand and medium sand, respectively, were found to be 2.3 MPa, 2.0 MPa, 2.6 MPa, whereas the flexural stresses were 0.46 MPa, 0.33 MPa, 0.67 MPa, which could resist rainfall droplet impact force. Overall, the proposed bio-method showed good rainwater infiltration control capacity and high bearing strength against the impact of heavy rainfalls, suggesting a good potential to mitigate the rainfall-induced landslides.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100023"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Durability of MICP-reinforced calcareous sand in marine environments: Laboratory and field experimental study","authors":"Yujie Li ,&nbsp;Yilong Li ,&nbsp;Zhen Guo ,&nbsp;Qiang Xu","doi":"10.1016/j.bgtech.2023.100018","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100018","url":null,"abstract":"<div><p>As eco-friendly methods, microbial induced carbonate precipitation (MICP) method was used to reinforce the calcareous sand in the South China Sea in this paper. The durability characteristics and deterioration mechanism of MICP-reinforced calcareous sand under various environment factors were investigated synthetically based on the unconfined compressive strength, mass loss rate and microscopic morphology in laboratory and field experimental study. Results show that, the unconfined compressive strength value of the sample is only 35.19 % of the initial strength, while the mass loss rate is about 6.69 % after 30-days of field marine environment erosion. MICP-reinforced calcareous sand shows the strongest resistance to temperature cycles, followed by dry-wet cycles, coupling effect of temperature and dry-wet cycle and salt spraying with drying cycles. MICP-reinforced calcareous sand exhibits the worst resistance to the field marine conditions, but the integrity of the sample could still be maintained after 30-days of field tests. The deterioration mechanism of MICP-reinforced calcareous sand is consistent under the various environmental cycles. First, the weakly cemented calcium carbonate crystals on the sample surface fall off, and then the hard-shell layer on the sample surface became weaker under various erosion. Finally, the internal cemented structure of the sample was gradually destroyed. The results indicated the utilization value of the MICP method in ocean engineering, but it is necessary to enhance the performance of the MICP-reinforced calcareous sand to ensure its protective effect after a certain environmental impact cycle.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100018"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49731834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving hydro-mechanical behavior of loess by a bio-strategy","authors":"Chaosheng Tang ,&nbsp;Xiaohua Pan ,&nbsp;Yaojia Cheng ,&nbsp;Xinlun Ji","doi":"10.1016/j.bgtech.2023.100024","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100024","url":null,"abstract":"<div><p>Loess is widely distributed all over the world, covering about 10% of the land surface on earth. China is one of the countries with the most serious loess soil erosion in the world, especially the loess plateau. This is mainly related to the poor water stability and mechanical properties of the loess. A new coupling method of bio-cementation (Microbially Induced Calcite Precipitation: MICP) and sand additive to improve the hydro-mechanical behavior of loess was proposed. The feasibility, coupling improvement mechanism and the effects of sand content, bio-cement treatment cycle and cementation solution (CS) concentration were investigated through a series of tests. The results indicated that the proposed method was effective to improve the water stability and structure strength of loess. The coupling improvement performance were positively related to the sand content. When the sand content was 40%, compared to bio-cement treatment, the coupling treatment was 9 times deeper in treatment depth, 3.5 times stronger in peak structure strength, and the sum slaking rate was less than half. The coupling improvement mechanism can be attributed to the form of the double layers including hard crust and cemented layer. With the addition of sand, the thickness, structure strength and water stability of the double layers increased. The main reason is that there were more interfacial voids between sand particles and loess particles, increasing the permeability of loess and treatment depth, forming more amount of calcium carbonates. Based on the experimental condition in this study, 1.0 M of CS concentration was the optimal spaying strategy to improve the hydro-mechanical properties of loess.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100024"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled experimental assessment and machine learning prediction of mechanical integrity of MICP and cement paste as underground plugging materials","authors":"Oladoyin Kolawole ,&nbsp;Rayan H. Assaad ,&nbsp;Matthew P. Adams ,&nbsp;Mary C. Ngoma ,&nbsp;Alexander Anya ,&nbsp;Ghiwa Assaf","doi":"10.1016/j.bgtech.2023.100020","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100020","url":null,"abstract":"<div><p>Compromised integrity of cementitious materials can lead to potential geo-hazards such as detrimental fluid flow to the wellbore (borehole), potential leakage of underground stored fluids, contamination of water aquifers, and other issues that could impact environmental sustainability during underground construction operations. The mechanical integrity of wellbore cementitious materials is critical to prevent wellbore failure and leakages, and thus, it is imperative to understand and predict the integrity of oilwell cement (OWC) and microbial-induced calcite precipitation (MICP) to maintain wellbore integrity and ensure zonal isolation at depth. Here, we investigated the mechanical integrity of two cementitious materials (MICP and OWC), and assessed their potential for plugging leakages around the wellbore. Further, we applied Machine Learning (ML) models to upscale and predict near-wellbore mechanical integrity at macro-scale by adopting two ML algorithms, Artificial Neural Network (ANN) and Random Forest (RF), using 100 datasets (containing 100 observations). Fractured portions of rock specimens were treated with MICP and OWC, respectively, and their resultant mechanical integrity (unconfined compressive strength, <em>UCS</em>; fracture toughness, <em>K</em>_<em>s</em>) were evaluated using experimental mechanical tests and ML models. The experimental results showed that although OWC (average <em>UCS</em> = 97 MPa, <em>K</em>_<em>s</em> = 4.3 MPa·√m) has higher mechanical integrity over MICP (average <em>UCS</em> = 86 MPa, <em>K</em>_<em>s</em> = 3.6 MPa·√m), the MICP showed an edge over OWC in sealing microfractures and micro-leakage pathways. Also, the OWC can provide a greater near-wellbore seal than MICP for casing-cement or cement-formation delamination with relatively greater mechanical integrity. The results show that the degree of correlation between the mechanical integrity obtained from lab tests and the ML predictions is high. The best ML algorithm to predict the macro-scale mechanical integrity of a MICP-cemented specimen is the RF model (R² for <em>UCS</em> = 0.9738 and <em>K</em>_<em>s</em> = 0.9988; MAE for <em>UCS</em> = 1.04 MPa and <em>K</em>_<em>s</em> = 0.02 MPa·√m). Similarly, for OWC-cemented specimen, the best ML algorithm to predict their macro-scale mechanical integrity is the RF model (R² for <em>UCS</em> = 0.9984 and <em>K</em>_<em>s</em> = 0.9996; MAE for <em>UCS</em> = 0.5 MPa and <em>K</em>_<em>s</em> = 0.01 MPa·√m). This study provides insights into the potential of MICP and OWC as near-wellbore cementitious materials and the applicability of ML model for evaluating and predicting the mechanical integrity of cementitious materials used in near-wellbore to achieve efficient geo-hazard mitigation and environmental protection in engineering and underground operations.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100020"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing biomineralization process efficiency with trained bacterial strains: A technical perspective","authors":"Chang Zhao ,&nbsp;Vahab Toufigh ,&nbsp;Jinxuan Zhang ,&nbsp;Yi Liu ,&nbsp;Wenjun Fan ,&nbsp;Xiang He ,&nbsp;Baofeng Cao ,&nbsp;Yang Xiao","doi":"10.1016/j.bgtech.2023.100017","DOIUrl":"https://doi.org/10.1016/j.bgtech.2023.100017","url":null,"abstract":"<div><p>Microorganisms have been essential in the natural world for millions of years, contributing significantly to environmental interaction. It has been disoverd that some bacteria are potential in geotechnical and environmental engineering due to their outstanding ability of biomineralization. Therefore, how to train bacteria as special and professional “workers” for biomineralization is increasingly a key topic in related research fields. This article briefly introduces the methods that are commonly utilized to improve the environmental adaptability and mineralization efficiency of bacteria, including microbial domestication, microbial mutation breeding, microbial targeted screening, and bio-stimulation, which make great implications to advance the field of biomineralization.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"1 2","pages":"Article 100017"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49731835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}