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Numerical investigation on the responses of existing single piles due to adjacent twin tunneling considering the lagging distance

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Underground Space 2023年第4期11卷 171-188页

作者： Chana Phutthananon Somkiat Lertkultanon Pornkasem Jongpradist Ochok Duangsano Suched Likitlersuang Pitthaya Jamsawang Construction Innovations and Future Infrastructures Research Center Department of Civil EngineeringFaculty of EngineeringKing Mongkut’s University of Technology ThonburiBangkok 10140Thailand Geotechnical and Foundation Engineering Co. LtdBangkok 10230Thailand Centre of Excellence in Geotechnical and Geoenvironmental Engineering Department of Civil EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand Soil Engineering Research Center Department of Civil EngineeringKing Mongkut’s University of Technology North BangkokBangkok 10800Thailand

This paper presents an assessment of the influence of the lagging distance between two horizontal tunnel faces of the side-by-side twin tunnels on the responses of the adjacent existing single pile by a series of three-dimensional numerical *** different relative positions between the pile tip and the tunnel are considered to cover the short and long pile *** responses of the existing pile in terms of pile head settlement,axial force,lateral movement and bending moment are considered and *** numerical results indicate that the lagging distance between twin tunnel faces significantly affects not only the soil movements but also the responses of the existing single *** critical case that produces unsatisfactory pile responses due to twin tunneling is when the lagging distance between the second tunnel and the preceding tunnel equals to the shield *** is recommended that the lagging distance be not less than three times of shield length when the two tunnels need to be concurrently excavated.

关键词： Twin tunnels Tunnel lagging distance Existing pile Finite element analysis Pile responses

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THE INFLUENCE OF NANOMATERIALS ON THE geotechnical PROPERTIES OF COHESIVE SOILS 22

THE INFLUENCE OF NANOMATERIALS ON THE GEOTECHNICAL PROPERTIE...

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22nd International Multidisciplinary Scientific Geoconference: Science and Technologies in Geology, Exploration and Mining, SGEM 2022

作者： Al-Rubaye, Ahmed Chirică, Anton Boți, Ioan Technical University of Civil Engineering Bucharest Department of Geotechnical and Foundation Engineering Romania

ISBN: (纸本)9786197603484

This paper experimentally investigated the effect of using nanomaterials to improve soft soils. Laboratory experimental tests were carried out on loessial soils collected from two different sites in Romania. Two different types of nanomaterials were used in this research, which is namely Nano-MgO with different percentages (0.5%, 0.75%, 1%, and 2%), and Nano-Al2O3 with percentages (0.5%,1%, and 2%), were added to the soil samples, to study their effect on the strength, consistency limits and compressibility of the soil. Treated soil samples were compacted using the modified Proctor test procedure and tested. The results of the investigations showed that the addition of nanomaterials to the soil may help to enhance the geotechnical properties. the compressibility and the strength of the treated soils increase with the increase in the amount of nanomaterials, Also, the addition of nanomaterials to the cohesive soils showed a small effect on the microstructure of the soil samples. As expected, the improvement is dependent on the type and amount of the nanomaterials. The results have been compared with 2% soil mixtures with cement. © 2022 International Multidisciplinary Scientific Geoconference. All rights reserved.

关键词： Aluminum oxide

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Comparative effects of twin-stacked tunnel excavation on adjacent structure using different simulation models

Comparative effects of twin-stacked tunnel excavation on adj...

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ITA-AITES World Tunnel Congress, WTC 2024

作者： Sittiamornporn, Nattavich Jongpradist, Pornkasem Phutthananon, Chana Chayaroon, Arthit Malaisree, Phattarawan Department of Civil Engineering Faculty of Engineering King Mongkut's University of Technology Thonburi Bangkok Thailand Geotechnical and Foundation Engineering Co. Ltd Bangkok Thailand MAA Consultants Co. Ltd Bangkok Thailand

ISBN: (纸本)9781032800424

The increase in transportation in urban areas has made it inevitable to excavate the twin-stacked tunnels and consequently affect adjacent structures. Therefore, an appropriate evaluation of the impact of tunnel excavation on the nearby building has been necessary to prevent the damage that may occur to the structure. In current engineering practice, there are various methods with different degrees of complexity to assess the impact on the building. This study presents a comparison of the effect caused by twin-stacked tunnel excavation on adjacent pile-supported structures by using three different simplified analysis methods. The results reveal that each method gives different results and the distance between the tunnels and the nearest pile affects the computed results. This study indicated that the tunneling analysis with the loaded pile method (FEM-LP) is more appropriate and conservative for the building impact assessment of the piled supported structures. The tunneling in green field (FEM-GF) conditions is proven to not be the conservative method. © 2024 The Author(s).

关键词： Piles

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Evaluation of impacts on existing structures induced by deep excavations in Bangkok MWA project

Evaluation of impacts on existing structures induced by deep...

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ITA-AITES World Tunnel Congress, WTC 2024

作者： Vonghirunyika, Phongkai Kroehong, Wunchock Yonjoho, Tananat Kandavorawong, Kangwan Chayaroon, Arthit Duangsano, Ochok Jongpradist, Pornkasem Department of Civil Engineering Faculty of Engineering and Architectural Uthenthawai Campus Rajamangala University of Technology Tawan-ok Bangkok Thailand Geotechnical and Foundation Engineering Co. Ltd Bangkok Thailand Department of Civil Engineering Faculty of Engineering King Mongkut’s University of Technology Thonburi Bangkok Thailand

ISBN: (纸本)9781032800424

The Metropolitan Waterworks Authority involves the construction of several shafts and a tunnel for the Water Transmission Tunnel Project in Bangkok, Thailand. In this project, numerous existing structures are located in close proximity to the underground construction areas. Consequently, these structures are susceptible to potential impacts due to the construction activities, particularly deep excavation of the shafts associated with excessive ground movements. This paper presents the evaluation of effects on the adjacent existing infrastructure resulting from the construction of two shafts with opening sizes of 12 m x 8 m and 10 m x 6 m, and the depth of excavation is around 30 m. A three-dimensional numerical analysis using PLAXIS 3D is carried out to investigate the responses, movements and imposed loads on the structures and piled foundations induced by the excavation in soft ground conditions. Extensive instrumentation and monitoring programs are implemented to observe such movements and to evaluate the serviceability of the existing structures. The monitoring results are in agreement with the analysis results and the construction has been successfully completed. © 2024 The Author(s).

关键词： Construction industry

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Observed response of maglev structure undercrossed by three shield tunnels in soft soil

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Underground Space 2022年第4期7卷 636-661页

作者： Dong-Mei Zhang Xiao-Chuang Xie Zhong-Kai Huang Mao-Zhu Peng Hong-Xin Zhu Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Centre for Offshore Foundation Systems University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009Australia Shanghai Municipal Engineering Design Institute(Group)Co. Ltd.China

This paper investigates the response of a maglev structure to three under-crossing tunnels of the Shanghai Metro Line *** minimal distance between the tunnels and pile groups of the maglev structure is only 1.5 m,thus the deformations of the maglev structure are strictly controlled for the serviceability of the operating maglev *** displacements of maglev piers and ground settlements during different tunnelling stages are monitored with an automatic measuring *** on the observed data,the ground settlement trough and displacements of maglev piers caused by the three shield tunnelling procedures are analyzed and *** maximal ground settlement after the completion of the three tunnelling procedures is -43 *** operate the existing maglev safely,practical construction control methods are applied,including synchronous grouting,adjustment of the shield status,shield-advancing speed control,and stabilisation of the soil chamber *** these countermeasures,the tunnel-induced deformations of maglev piers are well below the predefined *** piers heave under the strict deformation criterion of 2.0 *** crossing project is finally completed without interruptions of the maglev operations by monitoring the *** presented project is a valuable example for the evaluation of shield tunnelling effects on the adjacent maglev structures and establishes criteria for similar projects in the future.

关键词： Maglev Multi-crossing Shield tunnelling Ground settlement Pier displacement

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Oblique impact breakage unification of nonspherical particles using discrete element method

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Particuology 2024年第7期90卷 61-71页

作者： Di Peng LiGe Wang Yuquan Lin Chongqiang Zhu Xizhong Chen Zhihui Liu Ruihuan Ge Shenzhen Research Institute of Shandong University Shenzhen 518057China Institute of Foundation Engineering China Academy of Building ResearchBeijing 100013China Ubiquitous Particle Ltd. TwickenhamLondon TW27AUUK Department of Smart Manufacturing and Engineering Software School of Qilu TransportationShandong UniversityJinan 250061China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China School of Transportation and Civil Engineering Shandong Jiaotong UniversityJinan 250357China School of Science and Engineering University of DundeeDundee DD14HNUK Department of Chemical Engineering School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Chemical and Biological Engineering University of SheffieldSheffield S13JDUK

Particle breakage commonly occurs during processing of particulate materials,but a mechanistic model of particle impact breakage is not fully *** article presents oblique impact breakage characteristics of nonspherical particles using discrete element method(DEM)*** different particle shapes,***,cuboidal and cylindrical,are *** spheres are agglomerated with bridging bonds to model the breakage characteristics under impact *** effect of agglomerate shapes on the breakage pattern,damage ratio,and fragment size distribution is fully *** using a newly proposed oblique impact model,unified breakage master surfaces are theoretically constructed for all the particle shapes under oblique impact *** developed approach can be applied to modelling particulate processes where nonspherical particles and oblique impact breakage are prevailing.

关键词： Breakage master curve Nonspherical particle Oblique impact Equivalent velocity Discrete element method(DEM) Bonded contact model

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The Swelling Characteristics of an Unsaturated Bio-cemented Sand-Bentonite Mixture: Analyzing the Effect of Bacterial Concentration and Suction

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Iranian Journal of Science and Technology - Transactions of Civil engineering 2025年 1-21页

作者： Niknam Safari Kouchi, Ebrahim Nikooee, Ehsan Habibagahi, Ghassem Niazi, Ali Nagel, Thomas Dept. of Civil and Environmental Engineering School of Engineering Shiraz University P.O.Box 71348-51156 Shiraz Iran Institute of Biotechnology Shiraz University Shiraz Iran Soil Mechanics and Foundation Engineering Geotechnical Institute Technische Universität Bergakademie Freiberg Freiberg Germany Department of Environmental Informatics Helmholtz Centre for Environmental Research GmbH (UFZ) Leipzig Germany

Swelling soils are among the most prevalent problematic soils worldwide. The presence of swelling soils beneath foundation of buildings, irrigation canals, pavements, railway tracks and other infrastructures threatens their proper functioning and integrity, due to the large volumetric deformation that these soils experience as a result of change in saturation. There are various traditional methods to reduce swelling potential of expansive soils, such as lime and cement treatment. However, eco-friendly techniques such as microbially-induced carbonate precipitation (MICP), favoring their lower CO₂ footprint, have received great attention recently as a green and sustainable substitute to the traditional additives. Despite recent studies on the swelling potential of MICP treated soils, little is known on the effect of microbially induced carbonate precipitation on the soil swelling potential at different suction levels. It is, thus, crucial to understand the effect of saturation change and suction level on the swelling characteristics of bio-cemented soils. In this study, hence, free swelling tests were performed on biocemented sand-bentonite mixtures exposed to different suction levels applied using the osmotic technique. The soil water retention curve is a fundamental property for characterizing mechanical and hydraulic characteristics of unsaturated soils. Therefore, water retention properties of the bio-cemented swelling soil samples were also examined at different suction levels and bacterial density (i.e., different cell densities of Sporosarcina pasteurii). Based on free-swell tests, it was discovered that the combination of bacterial concentration and suction plays a crucial role in reducing soil swelling in biocemented soils. A minimum reduction of 67% in the free swell index of the sand-bentonite mixture was observed by treating the soil with a bacterial solution of OD = 1, regardless of the applied suction. XRD and SEM analysis of the treated sampl

关键词： Biocementation Osmotic Soil water retention curve Sporosarcina pasteurii Suction Swelling

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RESEARCH CONCERNING THE UPCYCLING OF AIR-COOLED BLAST FURNACE SLAG FROM OLD CĂLAN DUMP AS ADMIXTURE IN CLINKER PRECURSOR

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UPB Scientific Bulletin, Series B: Chemistry and Materials Science 2024年第4期86卷 231-244页

作者： Timiș, Andrei-Lucian Pencea, Ion Karas, Zbynek Priceputu, Adrian Ungureanu, Constantin Niculescu, Florentina Turcu, Ramona-Nicoleta Marcu, Dragoș-Florin Ciucă, Sorin Iacob, Gheorghe Doctoral School of the Materials Science and Engineering Faculty National University of Science and Technology POLITEHNICA Bucharest 313 Splaiul Independenţei Bucharest Romania Destro Kladno s.r.o. Sykorice 216 Zbecno Czech Republic Department of Geotechnical and Foundation Engineering Technical University of Civil Engineering 124 Lacul Tei Bucharest Romania Department of Geological Engineering Faculty of Geology and Geophysics University of Bucharest 6 Traian Vuia Bucharest Romania Faculty of Materials Science and Engineering National University of Science and Technology POLITEHNICA Bucharest 313 Splaiul Independentei Bucharest Romania

Cement is produced at large scale worldwide i.e., more than 4 billion tonnes. Romania produced circa 10.2 tonnes in 2022. 1.5 tonne, mainly limestone (≈70%wt.) and clay (21%wt.), is consumed for 1 tonne of clinker while 0.9 tonne of CO2 is released in atmosphere. Also, energy consumption per tonne of clinker ranges from 3.68 to 6.87 gigajoules. Hence, there is a higher preoccupation to find out solutions for greening the cement industry. One of the best solutions is to replace the genuine raw materials with waste or by-product like ferrous slag. This paper shows that the substitution of a part of genuine clinker precursors with air-cooled blast furnace slag (ACBFS) has at least 3 advantages i.e., preserves genuine irreplaceable resources, diminish energy consumption and reduces the CO2 footprint as ACBFS do not contain significant free CaO. The paper addresses the main technological characteristics of the clinker precursors i.e., grindability and clinker ability of four ACBFS admixed receipts. For a better valorization of the ACBFS deposited in Călan dump further research are envisaged to find out the optimum receipt of the ACBFS admixed clinker precursor. © 2024, Politechnica University of Bucharest. All rights reserved.

关键词： Blast furnaces

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Experimental Study and Numerical Simulation of the Wetting Settlement of Remolded Loess

Experimental Study and Numerical Simulation of the Wetting S...

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2023 International Conference on Applied Mechanics, Materials Physics, and engineering Structures, MMPES 2023

作者： Cao, Jie Pang, Bo Li, Youfeng Zhao, Haiyuan Lü, Xilin China JIKAN Research Institute of Engineering Investigations and Design Co. Ltd. SHANXI Xi'an710043 China Shanxi Key Laboratory of Engineering Behavior and Foundation Treatment for Special Soil Shanxi Xi'an710043 China Department of Geotechnical Engineering Tongji University Shanghai200092 China

By conducting collapsibility test, the changing rule of collapsibility coefficient of remolded loess is obtained. According to the numerical simulation method of equivalent humidity field with temperature field, the collapsibility coefficient is converted into temperature change, so the calculation of wetting settlement is realized. The results show that the collapsibility coefficient of loess decreases significantly with the increase of compaction degree and initial water content. It increases first and then decreases with the increase of overlying pressure at lower compaction degree, while increases gradually with the increase of overlying pressure at higher compaction degree. The numerical simulation based on the theory of equivalent humidity field with temperature field can accurately simulate the wetting settlement test results of remolded loess. © Published under licence by IOP Publishing Ltd.

关键词： Wetting

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Research on static load test results of compresive and tensile piles in soft soil 7

Research on static load test results of compresive and tensi...

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7th International Conference on Hydraulic and Civil engineering and Smart Water Conservancy and Intelligent Disaster Reduction Forum, ICHCE and SWIDR 2021

作者： Xu, Qi-Yan Lou, Xiao-Ming Technology Center Shanghai Qiangjin Foundation Engineering Co. Ltd Shanghai China Tongji University Department of Geotechnical Engineering Shanghai China

ISBN: (纸本)9781665408653

In order to study the differences of vertical bearing capacity and load transfer mechanism of single pile under compressive and tensile conditions, compressive and tensile static load tests of bored piles were carried out on a pile foundation project in Shanghai. The results show that due to the partial enlarger of the tensile pile diameter during construction, the pile body cracks and soil shear failure occurs, causing the uplifting displacement to be too large and the bearing capacity has much less than the bearing capacity of compressive piles. The ratio of pile end resistance to pile top load of compressive pile is very small, which the maximum does not exceed 1.5%. Therefore, it is unreasonable to blindly increase the pile length to enter hard soil layer. The pile side friction of compressive piles tends to decrease along the depth direction, and the compressive piles present semi-spindle-shaped distribution law of 'large middle and small ends', so pile side grouting is often adopted in the middle and lower part of the pile section to increase its vertical carrying capacity. © 2021 IEEE.

关键词： Piles

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