Abstract The accessibility to rheological parameters for concrete is becoming more and more relevant. This is mainly related to the constantly emerging challenges, such as not only the development of high-strength concretes is progressing very fast but also the simulation of the flow behaviour is of high importance. The main problem, however, is that the rheological characterisation of fresh concrete is not possible via commercial rheometers. The so-called concrete rheometers provide valuable relative values for comparing different concretes, but they cannot measure absolute values. Therefore, we developed an adaptive coaxial concrete rheometer (ACCR) that allows the measurement of fresh concrete with particles up to d max = 5.5 mm {d}_{{rm{max }}}=5.5hspace{.5em}{rm{mm}} . The comparison of the ACCR with a commercial rheometer showed very good agreement for selected test materials (Newtonian fluid, shear thinning fluid, suspension, and yield stress fluid), so that self-compacting concrete was subsequently measured. Since these measurements showed a very high reproducibility, the rheological properties of the fresh concrete could be determined with high accuracy. The common flow models (Bingham (B), Herschel–Bulkley, modified Bingham (MB) models) were also tested for their applicability, with the Bingham and the modified Bingham model proving to be the best suitable ones.
{"title":"Development of an adaptive coaxial concrete rheometer and rheological characterisation of fresh concrete","authors":"Sebastian Josch, Steffen Jesinghausen, H. Schmid","doi":"10.1515/arh-2022-0140","DOIUrl":"https://doi.org/10.1515/arh-2022-0140","url":null,"abstract":"Abstract The accessibility to rheological parameters for concrete is becoming more and more relevant. This is mainly related to the constantly emerging challenges, such as not only the development of high-strength concretes is progressing very fast but also the simulation of the flow behaviour is of high importance. The main problem, however, is that the rheological characterisation of fresh concrete is not possible via commercial rheometers. The so-called concrete rheometers provide valuable relative values for comparing different concretes, but they cannot measure absolute values. Therefore, we developed an adaptive coaxial concrete rheometer (ACCR) that allows the measurement of fresh concrete with particles up to d max = 5.5 mm {d}_{{rm{max }}}=5.5hspace{.5em}{rm{mm}} . The comparison of the ACCR with a commercial rheometer showed very good agreement for selected test materials (Newtonian fluid, shear thinning fluid, suspension, and yield stress fluid), so that self-compacting concrete was subsequently measured. Since these measurements showed a very high reproducibility, the rheological properties of the fresh concrete could be determined with high accuracy. The common flow models (Bingham (B), Herschel–Bulkley, modified Bingham (MB) models) were also tested for their applicability, with the Bingham and the modified Bingham model proving to be the best suitable ones.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44476630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Assessing the stress distribution within the slope in geotechnical engineering is critical. Despite the widely available numerical methods, no analytical solutions are available for determining the stress distribution within a slope under general loading conditions. This study presents a method of analytically approximating elastic stresses within a slope of arbitrary inclination subject to general surcharges and supporting forces. The prototype model of this problem is equivalent to a superposition of two sub-models: a half-plane body subjected to an initial earth stress field as well as surcharges on the crest (Model I) and a slope loaded by the release stresses caused by excavation, together with supporting forces on its inclined surface and bottom (Model II). The former stresses can be calculated analytically using Flamant’s solution, and the latter stresses can be further thought of as being composed of two additional components: one in an infinite plane with a half-infinite hole loaded by virtual tractions upon hole’s boundary (Model II1), which can be analytically approximated, and the other in a half-plane subjected to virtual tractions along the ground surface (Model II2), which can be calculated analytically as well. The two sets of virtual tractions that lead to stresses in Model II are calculated using an iterative process. The current approach provides analytical approximations of elastic stress solutions for slopes that are sufficiently close to the exact ones as accurate as much. A case study demonstrates that such solutions are in good agreement with those of the finite-element method’s over the entire region, the stresses within the region up to 10−11 times the slope’s height away from the slope toe can also be accurately determined using the current method. With this method, contour plots of stresses within a slope inclined at various angles are presented, which can be applied directly in practical engineering.
{"title":"Semi-analytical method for solving stresses in slope under general loading conditions","authors":"P. Wu, Xuejun Sun, Dayong Zhu Zhu","doi":"10.1515/arh-2022-0156","DOIUrl":"https://doi.org/10.1515/arh-2022-0156","url":null,"abstract":"Abstract Assessing the stress distribution within the slope in geotechnical engineering is critical. Despite the widely available numerical methods, no analytical solutions are available for determining the stress distribution within a slope under general loading conditions. This study presents a method of analytically approximating elastic stresses within a slope of arbitrary inclination subject to general surcharges and supporting forces. The prototype model of this problem is equivalent to a superposition of two sub-models: a half-plane body subjected to an initial earth stress field as well as surcharges on the crest (Model I) and a slope loaded by the release stresses caused by excavation, together with supporting forces on its inclined surface and bottom (Model II). The former stresses can be calculated analytically using Flamant’s solution, and the latter stresses can be further thought of as being composed of two additional components: one in an infinite plane with a half-infinite hole loaded by virtual tractions upon hole’s boundary (Model II1), which can be analytically approximated, and the other in a half-plane subjected to virtual tractions along the ground surface (Model II2), which can be calculated analytically as well. The two sets of virtual tractions that lead to stresses in Model II are calculated using an iterative process. The current approach provides analytical approximations of elastic stress solutions for slopes that are sufficiently close to the exact ones as accurate as much. A case study demonstrates that such solutions are in good agreement with those of the finite-element method’s over the entire region, the stresses within the region up to 10−11 times the slope’s height away from the slope toe can also be accurately determined using the current method. With this method, contour plots of stresses within a slope inclined at various angles are presented, which can be applied directly in practical engineering.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47129938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chloé Faverjon, Mohamed Yousfi, Caroline Parajua-sejil, Vivien Truchot, Jannick Duchet-Rumeau
Abstract A dominant extensional flow mixing device (Reactor/Elongational Flow MiXer; RMX) was used to prepare styrene-butadiene rubber (SBR)/silica nanocomposites with high physical performances. First, the processing parameters such as the temperature, number of mixing cycles, and sequenced mixing protocol have been optimized. Thereafter, the morphological structure of different compounds was probed using scanning and transmission electron microscopy. The prediction of the flow properties during processing of uncured materials were modeled using the dynamic and capillary rheometry. The thermo-mechanical sweep behavior of the as-prepared silica-filled SBR specimens was also investigated. By comparing with SBR/silica compounds prepared by the internal mixer, it was proven that elongational flow mixing process can not only reduce mixing energy consumption but also make the manufactured parts to have high state of dispersion, excellent viscoelastic properties, high extensional and yield stresses, and high elastic and rubbery moduli. This study highlights the potential of the elongational flow mixing as an innovative processing approach which is compatible with the industrial expectations for the fast manufacturing of high-performance silica and carbon black filled rubber compounds.
{"title":"Elongational flow mixing: A novel innovative approach to elaborate high-performance SBR-based elastomer compounds","authors":"Chloé Faverjon, Mohamed Yousfi, Caroline Parajua-sejil, Vivien Truchot, Jannick Duchet-Rumeau","doi":"10.1515/arh-2023-0105","DOIUrl":"https://doi.org/10.1515/arh-2023-0105","url":null,"abstract":"Abstract A dominant extensional flow mixing device (Reactor/Elongational Flow MiXer; RMX) was used to prepare styrene-butadiene rubber (SBR)/silica nanocomposites with high physical performances. First, the processing parameters such as the temperature, number of mixing cycles, and sequenced mixing protocol have been optimized. Thereafter, the morphological structure of different compounds was probed using scanning and transmission electron microscopy. The prediction of the flow properties during processing of uncured materials were modeled using the dynamic and capillary rheometry. The thermo-mechanical sweep behavior of the as-prepared silica-filled SBR specimens was also investigated. By comparing with SBR/silica compounds prepared by the internal mixer, it was proven that elongational flow mixing process can not only reduce mixing energy consumption but also make the manufactured parts to have high state of dispersion, excellent viscoelastic properties, high extensional and yield stresses, and high elastic and rubbery moduli. This study highlights the potential of the elongational flow mixing as an innovative processing approach which is compatible with the industrial expectations for the fast manufacturing of high-performance silica and carbon black filled rubber compounds.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135955019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Shallow urban tunnels with super-large sections in weak soils may experience much more devastating seismic hazards than conventionally deep tunnels in seismically vulnerable areas. This study investigates the seismic response and isolation technology for the largest comprehensive urban pipe gallery in the Xiong’an New Area, Hebei Province, China, using seismic simulation. First, the engineering background, static-seismic model, dynamic motions, and measuring points of the numerical simulation are introduced. Then, using the finite difference method to explore seismic behaviors of the super-large comprehensive urban pipe gallery under strong earthquake excitations are explored. The indexes including the deformation, the stress, the internal force, and the safety factor of segments are analyzed. Meanwhile, the aseismic effects of three proposed isolation schemes (namely, the cushion scheme, the partial buffer layer, and the integral buffer layer), which are proposed to be employed in the super-large comprehensive urban pipe gallery, are explored comparatively. The result shows that the integral buffer layer presents the most dramatic seismic isolation effect (97.85%), followed by the partial buffer layer (22.58%), and the cushion (15.07%). The integral buffer layer scheme is recommended to be employed in the seismic design for the present super-large pipe gallery. These conclusions can give scientific guidance for the seismic design of the super-large urban tunnels.
{"title":"Application of isolation technology in shallow super-large comprehensive pipe galleries in seismically vulnerable areas with weak soils","authors":"Jianfei Ma, G. Cui, S. He, Xiabing Liu","doi":"10.1515/arh-2022-0150","DOIUrl":"https://doi.org/10.1515/arh-2022-0150","url":null,"abstract":"Abstract Shallow urban tunnels with super-large sections in weak soils may experience much more devastating seismic hazards than conventionally deep tunnels in seismically vulnerable areas. This study investigates the seismic response and isolation technology for the largest comprehensive urban pipe gallery in the Xiong’an New Area, Hebei Province, China, using seismic simulation. First, the engineering background, static-seismic model, dynamic motions, and measuring points of the numerical simulation are introduced. Then, using the finite difference method to explore seismic behaviors of the super-large comprehensive urban pipe gallery under strong earthquake excitations are explored. The indexes including the deformation, the stress, the internal force, and the safety factor of segments are analyzed. Meanwhile, the aseismic effects of three proposed isolation schemes (namely, the cushion scheme, the partial buffer layer, and the integral buffer layer), which are proposed to be employed in the super-large comprehensive urban pipe gallery, are explored comparatively. The result shows that the integral buffer layer presents the most dramatic seismic isolation effect (97.85%), followed by the partial buffer layer (22.58%), and the cushion (15.07%). The integral buffer layer scheme is recommended to be employed in the seismic design for the present super-large pipe gallery. These conclusions can give scientific guidance for the seismic design of the super-large urban tunnels.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47835422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract It is known that concrete with high ductility reduces fatalities because it absorbs more energy during an earthquake. The aim of this study is to increase the ductility of concrete by using glass fiber mesh (GFM) left over from the use of plaster in structures and to support sustainability by reusing waste materials in concrete. Another aim is to contribute to the economy by using waste fibers instead of expensive fibers such as carbon and polypropylene in concrete. Two types of concrete were used: class C25 concrete and self-compacting concrete. The specified number of GFM materials was cut into 3 cm wide pieces and placed in 10 cm × 10 cm × 50 cm concrete beam specimens in varying numbers. It was found that the flexural values of the obtained specimens gave slightly better results than the prepared reference specimen. In addition, the increasing stress zones in the beams were visualized using the ANSYS software.
{"title":"The ductility performance of concrete using glass fiber mesh in beam specimens","authors":"Aylin Özodabaş","doi":"10.1515/arh-2023-0109","DOIUrl":"https://doi.org/10.1515/arh-2023-0109","url":null,"abstract":"Abstract It is known that concrete with high ductility reduces fatalities because it absorbs more energy during an earthquake. The aim of this study is to increase the ductility of concrete by using glass fiber mesh (GFM) left over from the use of plaster in structures and to support sustainability by reusing waste materials in concrete. Another aim is to contribute to the economy by using waste fibers instead of expensive fibers such as carbon and polypropylene in concrete. Two types of concrete were used: class C25 concrete and self-compacting concrete. The specified number of GFM materials was cut into 3 cm wide pieces and placed in 10 cm × 10 cm × 50 cm concrete beam specimens in varying numbers. It was found that the flexural values of the obtained specimens gave slightly better results than the prepared reference specimen. In addition, the increasing stress zones in the beams were visualized using the ANSYS software.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136204448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Based on the pit excavation project in a station of Lanzhou Metro, the horizontal displacement of bored piles, the ground settlement around the foundation pit, and the supporting axial force in the foundation pit were tested on site. The changing rules and influencing factors of horizontal displacement of external and internal bracing piles during foundation pit construction are analyzed. Comparing the measured results with the numerical simulation results, the results show that the finite element calculation results can meet the engineering needs, the pile-support system can effectively control the deformation of the foundation pit, and the bottom of the outer pit has an obvious uplift. The numerical simulation is used to study the influence of different working conditions on the deformation of the foundation pit. The results show that the inner support of the foundation pit can control soil deformation more effectively than the outer support of the foundation pit. The study can provide a reference for the construction of such foundation pit in Lanzhou in the future.
{"title":"Monitoring and numerical simulation analysis of a pit-in-pit excavation of the first branch line of Lanzhou Metro","authors":"Hui Tao, Shuaihua Ye, Shicheng Zhang","doi":"10.1515/arh-2023-0111","DOIUrl":"https://doi.org/10.1515/arh-2023-0111","url":null,"abstract":"Abstract Based on the pit excavation project in a station of Lanzhou Metro, the horizontal displacement of bored piles, the ground settlement around the foundation pit, and the supporting axial force in the foundation pit were tested on site. The changing rules and influencing factors of horizontal displacement of external and internal bracing piles during foundation pit construction are analyzed. Comparing the measured results with the numerical simulation results, the results show that the finite element calculation results can meet the engineering needs, the pile-support system can effectively control the deformation of the foundation pit, and the bottom of the outer pit has an obvious uplift. The numerical simulation is used to study the influence of different working conditions on the deformation of the foundation pit. The results show that the inner support of the foundation pit can control soil deformation more effectively than the outer support of the foundation pit. The study can provide a reference for the construction of such foundation pit in Lanzhou in the future.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135562844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In order to address the impact of the perforated parameters on the mechanical properties of the plate, the ultimate strength of hyper-ellipse flanged-perforated plates under uniaxial compression stress is numerically investigated in this article. The four edges of the flanged-perforated plate are only supported in the out-of-plane direction while the plate is exposed to uniaxial compressive loads. The impact of the cutout size, flange height, cutout position, rotation angle, and cutout form on the ultimate bearing capacity of the perforated plate with varied thicknesses is investigated and compared through a series of elasto-plastic buckling analyses using the ANSYS software. The structure’s stress and deformation analysis is then used to explain the results of the ultimate strength test. The flange efficiently raises the maximum bearing strength of the structure with cutouts. For the limit strength of thick plate, the cutout size, elliptical shape, cutout rotation angle, and cutout position have considerably more of an impact than they do on the maximum bearing capacity of thin plate. The findings can assist the structural layout of this sort of perforated plate, and the right cutout parameters should be chosen in accordance with the various performance specifications.
{"title":"Ultimate strength of hyper-ellipse flanged-perforated plates under uniaxial compression loading","authors":"Wang Wensheng, Ning Huijun, Shang Xin","doi":"10.1515/arh-2022-0139","DOIUrl":"https://doi.org/10.1515/arh-2022-0139","url":null,"abstract":"Abstract In order to address the impact of the perforated parameters on the mechanical properties of the plate, the ultimate strength of hyper-ellipse flanged-perforated plates under uniaxial compression stress is numerically investigated in this article. The four edges of the flanged-perforated plate are only supported in the out-of-plane direction while the plate is exposed to uniaxial compressive loads. The impact of the cutout size, flange height, cutout position, rotation angle, and cutout form on the ultimate bearing capacity of the perforated plate with varied thicknesses is investigated and compared through a series of elasto-plastic buckling analyses using the ANSYS software. The structure’s stress and deformation analysis is then used to explain the results of the ultimate strength test. The flange efficiently raises the maximum bearing strength of the structure with cutouts. For the limit strength of thick plate, the cutout size, elliptical shape, cutout rotation angle, and cutout position have considerably more of an impact than they do on the maximum bearing capacity of thin plate. The findings can assist the structural layout of this sort of perforated plate, and the right cutout parameters should be chosen in accordance with the various performance specifications.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42502805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract To obtain better radiation shielding, a new polyester has been made by the combination of 40 wt% of polyester and 30 wt% of fine waste marble mixed along with PbO (30–0) wt% and Bi2O3 (0–30) wt%. A few significant shielding parameters such as linear attenuation coefficient (LAC), half-value layer (HVL), mean free path (MFP), and effective atomic number (Z eff) have been measured experimentally using an HPGe detector. Theoretical values have also been calculated using XCOM software. With the aim of validating the experimental setup, the measured shielding parameters, such as LAC and HVL, have been compared with their theoretical analogs. At 0.662 MeV energy, the prepared new polyester’s HVL and MFP exhibited that the sample PWPBi-10 composed of polyester (40 wt%), fine waste marble (30 wt%), PbO (20 wt%), and Bi2O3 (10 wt%) provides the best shielding ability among other studied polyesters herein. The MFP behavior indicates that the ratio of Bi2O3 and PbO on these new polyesters has a direct impact on their radiation-shielding properties. It is noteworthy that new polyester PWPBi-10 exposed the lowest value of MFP compared to the rest of the studied samples. In conclusion, considering all the measured shielding parameters, it can be stated that the sample PWPBi-10 has the ultimate radiation diffusion capability among the rest of the studied samples.
{"title":"An experimental investigation into the radiation-shielding performance of newly developed polyester containing recycled waste marble and bismuth oxide","authors":"A. Almuqrin, S. Yasmin, M. Abualsayed, M. Elsafi","doi":"10.1515/arh-2022-0153","DOIUrl":"https://doi.org/10.1515/arh-2022-0153","url":null,"abstract":"Abstract To obtain better radiation shielding, a new polyester has been made by the combination of 40 wt% of polyester and 30 wt% of fine waste marble mixed along with PbO (30–0) wt% and Bi2O3 (0–30) wt%. A few significant shielding parameters such as linear attenuation coefficient (LAC), half-value layer (HVL), mean free path (MFP), and effective atomic number (Z eff) have been measured experimentally using an HPGe detector. Theoretical values have also been calculated using XCOM software. With the aim of validating the experimental setup, the measured shielding parameters, such as LAC and HVL, have been compared with their theoretical analogs. At 0.662 MeV energy, the prepared new polyester’s HVL and MFP exhibited that the sample PWPBi-10 composed of polyester (40 wt%), fine waste marble (30 wt%), PbO (20 wt%), and Bi2O3 (10 wt%) provides the best shielding ability among other studied polyesters herein. The MFP behavior indicates that the ratio of Bi2O3 and PbO on these new polyesters has a direct impact on their radiation-shielding properties. It is noteworthy that new polyester PWPBi-10 exposed the lowest value of MFP compared to the rest of the studied samples. In conclusion, considering all the measured shielding parameters, it can be stated that the sample PWPBi-10 has the ultimate radiation diffusion capability among the rest of the studied samples.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47262380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Taking the twin-tunnel shield tunnel of the urban rail transit in Lanzhou City as an example, this article applies the hardening soil small criterion and utilizes finite element software to simulate the excavation process of the undercrossing Yellow River tunnel. The analysis focuses on the deformation effects and axial force variations of nearby bridge foundations in three directions: vertical to the tunnel, along the tunnel, and the vertical direction. The simulation results are compared with monitoring data. The findings indicate that shield tunnel construction increases the deformation of bridge foundations in the vertical and tunnel directions, while mitigating the deformation in the vertical direction. The influence is more significant as the distance between the tunnel and the foundations decreases. The redistribution of stress due to soil disturbance causes foundation deformation, and the magnitude of foundation deformation reflects the extent of soil disturbance. The simulated vertical displacement of the pile head is consistent with the trend observed in the field measurements. The simulation results generally align with the conclusion that the tunnel has minimal impact on the soil beyond a distance of 3–5 times the tunnel diameter.
{"title":"Numerical analysis of the impact of excavation for undercrossing Yellow River tunnel on adjacent bridge foundations","authors":"Liangliang Xin, Shuaihua Ye, Dengqun Wang","doi":"10.1515/arh-2023-0104","DOIUrl":"https://doi.org/10.1515/arh-2023-0104","url":null,"abstract":"Abstract Taking the twin-tunnel shield tunnel of the urban rail transit in Lanzhou City as an example, this article applies the hardening soil small criterion and utilizes finite element software to simulate the excavation process of the undercrossing Yellow River tunnel. The analysis focuses on the deformation effects and axial force variations of nearby bridge foundations in three directions: vertical to the tunnel, along the tunnel, and the vertical direction. The simulation results are compared with monitoring data. The findings indicate that shield tunnel construction increases the deformation of bridge foundations in the vertical and tunnel directions, while mitigating the deformation in the vertical direction. The influence is more significant as the distance between the tunnel and the foundations decreases. The redistribution of stress due to soil disturbance causes foundation deformation, and the magnitude of foundation deformation reflects the extent of soil disturbance. The simulated vertical displacement of the pile head is consistent with the trend observed in the field measurements. The simulation results generally align with the conclusion that the tunnel has minimal impact on the soil beyond a distance of 3–5 times the tunnel diameter.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44352155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Based on the collected soil property index test data of more than 2,500 groups of inland fluvial-lacustrine soft soil, the correlation of physical and mechanical parameters of this soft soil was systematically analyzed. The results show that the physical indexes of inland fluvial-lacustrine soft soil are close to that of marine soft soil, while its mechanical indexes are higher. However, the variation coefficient of its mechanical indexes is much larger than that of the physical indexes. In addition, it is found that the cone penetration parameters of this soft soil are significantly correlated with its physical and mechanical indexes by establishing a series of empirical relationships between the static point resistance and the natural unit weight, the liquidity index, the quick shear cohesion, and vane shear strength. On the basis of the previous research results, the disturbance strength of inland fluvial-lacustrine soft soil can be converted into in situ strength by deriving the theoretical formula between the vane shear strength and the disturbance degree. The calculation process of the above conversion relation is explained in detail through an engineering case, which indicates that the theoretical formulas have good applicability for inland fluvial-lacustrine soft soil.
{"title":"Correlation analysis of physical and mechanical parameters of inland fluvial-lacustrine soft soil based on different survey techniques","authors":"Liujun Zhang, Youqiang Qiu, Tong Wu, W. Zhang","doi":"10.1515/arh-2022-0145","DOIUrl":"https://doi.org/10.1515/arh-2022-0145","url":null,"abstract":"Abstract Based on the collected soil property index test data of more than 2,500 groups of inland fluvial-lacustrine soft soil, the correlation of physical and mechanical parameters of this soft soil was systematically analyzed. The results show that the physical indexes of inland fluvial-lacustrine soft soil are close to that of marine soft soil, while its mechanical indexes are higher. However, the variation coefficient of its mechanical indexes is much larger than that of the physical indexes. In addition, it is found that the cone penetration parameters of this soft soil are significantly correlated with its physical and mechanical indexes by establishing a series of empirical relationships between the static point resistance and the natural unit weight, the liquidity index, the quick shear cohesion, and vane shear strength. On the basis of the previous research results, the disturbance strength of inland fluvial-lacustrine soft soil can be converted into in situ strength by deriving the theoretical formula between the vane shear strength and the disturbance degree. The calculation process of the above conversion relation is explained in detail through an engineering case, which indicates that the theoretical formulas have good applicability for inland fluvial-lacustrine soft soil.","PeriodicalId":50738,"journal":{"name":"Applied Rheology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48979363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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