Biogeotechnics最新文献

{"title":"Miniaturized device to measure urease activity in the soil interstitial fluid using wenner method","authors":"Rafaela Cardoso ,&nbsp;Thomas Drouinot ,&nbsp;Susana Cardoso de Freitas","doi":"10.1016/j.bgtech.2024.100120","DOIUrl":"10.1016/j.bgtech.2024.100120","url":null,"abstract":"<div><div>This paper presents a microdevice developed to measure the electrical conductivity of a liquid or a saturated porous medium using Wenner method. It is developed in the context of biocementation as soil improvement technique, which is used in Civil Engineering applications to produce calcium carbonate through bacterial or enzymatic activity, replacing the use of other binder materials such as cement or resins, and therefore reducing carbon footprint. The microdevice was used to measure urease activity in the soil interstitial fluid, to investigate if bacterial activity could be affected by the presence of the particles and tortuosity from pore geometry. Such analysis is important to understand biocementation mechanism inside the soil and helps to improve the design of such treatment solutions. The device is basically a squared reservoir printed in polypropylene using a 3D printing machine, incorporating stainless steel electrodes in its base. The electrical resistivity was computed adopting Wenner method, by connecting 4 PCB electrodes to a signal generator and an oscilloscope for measuring the voltage when a AC current of 1 mA was applied. Both square and sinusoidal waves with 5 kHz frequency were selected among other frequencies. The measurements were adjusted during the calibration of the microdevice, done using standard salt solutions with known electrical conductivity measured using an electrical conductivity probe. For the bacterial activity measurements, the bacterial and urea solutions were added to a uniform-graded size quarzitic sand (average diameter 0.3 mm) placed inside the microdevice and covering completely the electrodes. Bacterial activity was not affected by the presence of the sand, which confirms that this treatment is effective for this type of soils.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal desorption remediation effects on soil biogeochemical properties and plant performance: Global meta-analysis","authors":"Jiaxin Liao ,&nbsp;Haowen Guo ,&nbsp;Sanandam Bordoloi ,&nbsp;Denian Li ,&nbsp;Yuanxiang Zhang ,&nbsp;Junjun Ni ,&nbsp;Haoran Yuan ,&nbsp;Xudong Zhao","doi":"10.1016/j.bgtech.2024.100140","DOIUrl":"10.1016/j.bgtech.2024.100140","url":null,"abstract":"<div><div>Soil contamination remains a global problem, and numerous studies have been published for investigating soil remediation. Thermal desorption remediation (TDR) can significantly reduce the contaminants in the soil within a short time and consequently has been used worldwide. However, the soil properties respond to TDR differently and are dependent on the experimental set-up. The causative mechanisms of these differences are yet to be fully elucidated. A statistical meta-analysis was thus undertaken to evaluate the TDR treatment effects on soil properties and plant performance. This review pointed out that soil clay was reduced by 54.2%, while soil sand content was enhanced by 15.2% after TDR. This might be due to the release of cementing agents from clay minerals that resulted in the formation of soil aggregates. Soil electrical conductivity enhanced by 69.5% after TDR, which might be due to the heating-induced loss of structural hydroxyl groups and the consequent liberation of ions. The treatment of TDR leads to the reduction of plant germination rate, length, and biomass by 19.4%, 44.8%, and 20.2%, respectively, compared to that of control soil. This might be due to the residue of contaminants and the loss of soil fertility during the thermal process that inhibited plant germination and growth. Soil pH and sulfate content increased with heating temperature increased, while soil enzyme activities decreased with thermal temperature increased. Overall, the results suggested that TDR treatment has inhibited plant growth as well as ecological restoration.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 3","pages":"Article 100140"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557605","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":"Climate impacts on deformation and instability of vegetated slopes","authors":"Qi Zhang ,&nbsp;Haiyi Zhong ,&nbsp;Haowen Guo ,&nbsp;Junjun Ni","doi":"10.1016/j.bgtech.2024.100139","DOIUrl":"10.1016/j.bgtech.2024.100139","url":null,"abstract":"<div><div>Eco-geotechnical engineering plays a pivotal role in enhancing global sustainability and upholding the performance of earthen structures. The utilization of vegetation to stabilise geotechnical infrastructures is widely recognized and embraced for its environmentally friendly attributes. The spectre of climate change further intensifies the focus on the effects of temperature and humidity on vegetated soil. Consequently, there is a pressing need for research exploring the influence of changing climates on vegetated infrastructures. Such research demands a holistic and interdisciplinary approach, bridging fields such as soil mechanics, botany, and atmospheric science. This review underscores key facets crucial to vegetated geotechnical infrastructures, encompassing climate projections, centrifuge modelling, field monitoring, and numerical methodologies.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 2","pages":"Article 100139"},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation on response of biocemented coral sand pile composite foundation under seismic waves","authors":"Xiangwei Fang ,&nbsp;Chao Chen ,&nbsp;Ganggang Zhou ,&nbsp;Zhixiong Chen ,&nbsp;Chunyan Wang ,&nbsp;Luqi Wang","doi":"10.1016/j.bgtech.2024.100136","DOIUrl":"10.1016/j.bgtech.2024.100136","url":null,"abstract":"<div><div>The biocemented coral sand pile composite foundation represents an innovative foundation improvement technology, utilizing Microbially Induced Carbonate Precipitation (MICP) to consolidate a specific volume of coral sand within the foundation into piles with defined strength, thereby enabling them to collaboratively bear external loads with the surrounding unconsolidated coral sand. In this study, a series of shaking table model tests were conducted to explore the dynamic response of the biocemented coral sand pile composite foundation under varying seismic wave types and peak accelerations. The surface macroscopic phenomena, excess pore water pressure ratio, acceleration response, and vertical settlement were measured and analysed in detail. Test results show that seismic wave types play a decisive role in the macroscopic surface phenomena and the response of the excess pore water pressure ratio. The cumulative settlement of the upper structure under the action of Taft waves was about 1.5 times that of El Centro waves and Kobe waves. The most pronounced liquefaction phenomena were recorded under the Taft wave, followed by the El Centro wave, and subsequently the Kobe wave. An observed positive correlation was established between the liquefaction phenomenon and the Aristotelian intensity of the seismic waves. However, variations in seismic wave types exerted minimal influence on the acceleration amplification factor of the coral sand foundation. Analysis of the acceleration amplification factor revealed a triphasic pattern—initially increasing, subsequently decreasing, and finally increasing again—as burial depth increased, in relation to the peak value of the input acceleration. This study confirms that the biocemented coral sand pile composite foundation can effectively enhance the liquefaction resistance of coral sand foundations.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 2","pages":"Article 100136"},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Architecture characterization of orchard trees for mechanical behavior investigations","authors":"Min Kyung Jeon ,&nbsp;Matthew Burrall ,&nbsp;Tae Hyuk Kwon ,&nbsp;Jason T. DeJong ,&nbsp;Alejandro Martinez","doi":"10.1016/j.bgtech.2024.100138","DOIUrl":"10.1016/j.bgtech.2024.100138","url":null,"abstract":"<div><div>Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems. This study explores the structural root architectures of orchard trees to understand the interplays between the mechanical behavior of roots and the root architecture. Full three-dimensional (3D) models of natural tree root systems, Lovell, Marianna, and Myrobalan, that were extracted from the ground by vertical pullout are reconstructed through photogrammetry and later skeletonized as nodes and root branch segments. Combined analyses of the full 3D models and skeletonized models enable a detailed examination of basic bulk properties and quantification of architectural parameters. While the root segments are divided into three categories, trunk root, main lateral root, and remaining roots, the patterns in branching and diameter distributions show significant differences between the trunk and main laterals versus the remaining lateral roots. In general, the branching angle decreases over the sequence of bifurcations. The main lateral roots near the trunk show significant spreading while the lateral roots near the ends grow roughly parallel to the parent root. For branch length, the roots bifurcate more frequently near the trunk and later they grow longer. Local thickness analysis confirms that the root diameter decays at a higher rate near the trunk than in the remaining lateral roots, while the total cross-sectional area across a bifurcation node remains mostly conserved. The histograms of branching angle, and branch length and thickness gradient can be described using lognormal and exponential distributions, respectively. This unique study presents data to characterize mechanically important structural roots, which may help link root architecture to the mechanical behaviors of root structures.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 2","pages":"Article 100138"},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development characteristics and quantitative analysis of cracks in root-soil complex during different growth periods under dry-wet cycles","authors":"Zhengjun Mao ,&nbsp;Xu Ma ,&nbsp;Mimi Geng ,&nbsp;Munan Wang ,&nbsp;Guangsheng Gao ,&nbsp;Yanshan Tian","doi":"10.1016/j.bgtech.2024.100121","DOIUrl":"10.1016/j.bgtech.2024.100121","url":null,"abstract":"<div><div>Repeated wet swelling and dry shrinkage of soil leads to the gradual occurrence of cracks and the formation of a complex fracture network. In order to study the development characteristics and quantitative analysis of cracks in root-soil complex in different growth periods under dry-wet cycles, the alfalfa root-loess complex was investigated during different growth periods under different dry-wet cycles, and a dry-wet cycle experiment was conducted. The crack rate, relative area, average width, total length, and the cracks fractal dimension in the root-soil complex were extracted; the crack development characteristics of plain soil were analyzed under the PG-DWC (dry-wet cycle caused by plant water management during plant growth period), as well as the crack development characteristics of root-soil complex under PG-DWC and EC-DWC (the dry-wet cycles caused by extreme natural conditions such as continuous rain); the effects of plant roots and dry-wet cycles on soil cracks were discussed. The results showed that the average crack width, crack rate, relative crack area, and total crack length of the alfalfa root-loess complex were higher than those of the plain soil during PG-DWC. The result indicated that compared with plain soil during PG-DWC, the presence of plant roots in alfalfa root-soil complex in the same growth period promoted the cracks development to some extent. The alfalfa root-soil complex crack parameters during different growth periods were relatively stable during PG-DWC (0 dry-wet cycle). During EC-DWC (1, 3, and 5 dry-wet cycles), the alfalfa root-loess complex crack parameters increased with the number of dry-wet cycles during different growth periods. Unlike PG-DWC, the EC-DWC accelerated crack development, and the degree of crack development increased with the number of dry-wet cycles. The existence of plant roots promoted crack development and expansion in the root-soil complex to a certain extent, and the dry-wet cycle certainly promoted crack development and expansion in the root-soil complex. This result contradicts the improvement in the root-soil complex's macro-mechanical properties during plant growth, due to differences in the mechanical properties of roots and soil. The research results will provide reference for the root soil complex crack development law and the design of slope protection by vegetation.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100121"},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141839789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved methods, properties, applications and prospects of microbial induced carbonate precipitation (MICP) treated soil: A review","authors":"Xuanshuo Zhang ,&nbsp;Hongyu Wang ,&nbsp;Ya Wang ,&nbsp;Jinghui Wang ,&nbsp;Jing Cao ,&nbsp;Gang Zhang","doi":"10.1016/j.bgtech.2024.100123","DOIUrl":"10.1016/j.bgtech.2024.100123","url":null,"abstract":"<div><div>Soil improvement is one of the most important issues in geotechnical engineering practice. The wide application of traditional improvement techniques (cement/chemical materials) are limited due to damage ecological environment and intensify carbon emissions. However, the use of microbially induced calcium carbonate precipitation (MICP) to obtain bio-cement is a novel technique with the potential to induce soil stability, providing a low-carbon, environment-friendly, and sustainable integrated solution for some geotechnical engineering problems in the environment. This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy. It systematically summarizes and overviews the mineralization mechanism, influencing factors, improved methods, engineering characteristics, and current field application status of the MICP. Additionally, it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement. This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand. Furthermore, we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future. The current review purports to provide insights for engineers and interdisciplinary researchers, and guidance for future engineering applications.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100123"},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biogenic construction: The new era of civil engineering","authors":"Hanlong Liu","doi":"10.1016/j.bgtech.2024.100130","DOIUrl":"10.1016/j.bgtech.2024.100130","url":null,"abstract":"<div><div>With the increasing demand for buildings and infrastructures and the mounting challenges associated with the current construction technologies such as high emission, high pollution, and high energy consumption, the civil engineering profession is at the crossroad for a transformation or upgrading before it can be put into tasks for these challenges. Inspired by the concept of harmonious coexistence between humans and nature, a new concept, biogenic construction, for civil engineering is proposed in this paper. The definition of biogenic construction is given. The framework and four components of biogenic construction are established. These include microbial construction, plant construction, animal construction, and bioinspired construction. Examples of each component are given. A new construction system for creating a more eco-friendly, healthier, and more sustainable environment for future civil engineering developments is also proposed.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100130"},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of grass plantation on the rainfall-induced instability of gentle loose fill slope","authors":"Pei Tai ,&nbsp;Fan Wu ,&nbsp;Bohan Bai ,&nbsp;Zhaofeng Li ,&nbsp;Rui Chen ,&nbsp;Lulu Zhang","doi":"10.1016/j.bgtech.2024.100101","DOIUrl":"10.1016/j.bgtech.2024.100101","url":null,"abstract":"<div><p>The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: one on a bare slope and the other on a slope planted with ryegrass. The slope angle of 25° is much lower than the internal friction angle of slope material (34.3°), which makes the model test fall well into the category of gentle slope. For the initially unsaturated bare slope, a rainfall event with return period of 18 years could trigger a rapid and retrogressive global sliding, which differs from previous findings that gentle slopes would only experience shallow failure. A sudden increase in pore-water pressure was simultaneously observed, which might be generated by the wetting-induced collapse of unsaturated loose soil. On the other hand, the stability of the slope with grass plantation was significantly enhanced, and it was able to withstand rainfall event more severe than those with a return period of 100 years, with only minimal deformation. The results suggest that the gain in shear strength due to ryegrass roots surpasses the additional sliding force caused by the increased water retention capability. Additionally, it is found that the abrupt change in pore pressure was no longer indicative of slope failure in the case of the grass-reinforced slope.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"2 4","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949929124000330/pdfft?md5=e559eef248da6ada511b94e9ec23f693&pid=1-s2.0-S2949929124000330-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141691018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of grassland vegetation roots on soil infiltration rate in Xiazangtan super large scale landslide distribution area in the upper reaches of the Yellow River, China","authors":"Peihao Zhang ,&nbsp;Guangyan Xing ,&nbsp;Xiasong Hu ,&nbsp;Changyi Liu ,&nbsp;Xilai Li ,&nbsp;Jimei Zhao ,&nbsp;Jiangtao Fu ,&nbsp;Haijing Lu ,&nbsp;Huatan Li ,&nbsp;Zhe Zhou ,&nbsp;Lei Yue ,&nbsp;Yabin Liu ,&nbsp;Guorong Li ,&nbsp;Haili Zhu","doi":"10.1016/j.bgtech.2024.100104","DOIUrl":"10.1016/j.bgtech.2024.100104","url":null,"abstract":"<div><p>In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River, this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area. Through experiments and numerical simulations, plant roots characteristics, soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed, and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed. The results show that the highest soil moisture infiltration capacity (FIR) is found on the shady slope of the enclosed grassland (2.25), followed by the sunny slope of the enclosed grassland (1.23) and the shady slope of the naturally grazed grassland (−0.87). Correlation analysis show that soil water content, root dry weight density, total soil porosity, number of forks and root length are positively correlated with infiltration rate (<em>P</em>＜0.05), whereas soil dry density is negatively correlated with infiltration rate (<em>P</em>＜0.05). The results of stepwise regression analyses show that soil water content, total soil porosity, root length and number of forks are the main factors affecting soil infiltration capacity. And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself. After 60 min of simulated rainfall, the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56% and 19.63%, respectively, comparing to those before rainfall. Therefore, in this study, the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content, soil total porosity and shear strength while decreasing soil dry density. The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"2 4","pages":"Article 100104"},"PeriodicalIF":0.0,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949929124000366/pdfft?md5=32eff534fe5d0bbb5e86dc6c67130180&pid=1-s2.0-S2949929124000366-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}