Finite-difference analysis of soft ground treatment with prefabricated vertical drains (PVDs) was performed using a newly developed consolidation model. The model uses the concept of multi-compression indices and coefficients of consolidation (CoCs) to investigate the behaviour of a soft ground deposit (pore water pressure dissipation, surface settlement and sub-layer ground settlement) and to validate the newly developed Consopro finite-difference procedure. The pre-consolidation pressures of the soft ground deposit were characterised using a combination of piezocone penetration profiling and constant rate-of-strain (CRS) consolidation tests (0.02%/min) on undisturbed samples that were retrieved from the Saigon premier container terminal in the south of Vietnam. After comparison of the back-calculated results with field-observed data, a correlation between the CoCs determined by CRS consolidation tests and the CoCs from piezocone dissipation tests, which were carried out after soil improvement, was determined.
{"title":"Analysis of prefabricated vertical drains with surcharge preloading of Hiep Phuoc clay","authors":"Cong-Oanh Nguyen, Thi Van-Tram Dao, Thi-Thanh Tran","doi":"10.1680/jgeen.21.00079","DOIUrl":"https://doi.org/10.1680/jgeen.21.00079","url":null,"abstract":"Finite-difference analysis of soft ground treatment with prefabricated vertical drains (PVDs) was performed using a newly developed consolidation model. The model uses the concept of multi-compression indices and coefficients of consolidation (CoCs) to investigate the behaviour of a soft ground deposit (pore water pressure dissipation, surface settlement and sub-layer ground settlement) and to validate the newly developed Consopro finite-difference procedure. The pre-consolidation pressures of the soft ground deposit were characterised using a combination of piezocone penetration profiling and constant rate-of-strain (CRS) consolidation tests (0.02%/min) on undisturbed samples that were retrieved from the Saigon premier container terminal in the south of Vietnam. After comparison of the back-calculated results with field-observed data, a correlation between the CoCs determined by CRS consolidation tests and the CoCs from piezocone dissipation tests, which were carried out after soil improvement, was determined.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135222535","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}
V. Sivakumar, J. Fanning, K. Gavin, S. Tripathy, A. Bradshaw, E. Murray, J. Black, S. Donohue
This paper presents data from an initial development stage of an ‘umbrella anchor’ concept. The anchor can be pushed into sand deposit in a folded arrangement to reduce installation loads. When a pull-out load is applied to the mooring line, the anchor deploys to create a large embedded plate anchor. Physical modelling was carried out in saturated sand-bed with the anchor installed at depths of up to 1.6 m and loaded vertically. During installation, liquefaction was generated at the tip of the anchor to reduce the penetration resistance. This enabled the anchor to be installed quickly and accurately to a target depth. The anchor could provide pull-out resistances comparable to anchor that was wished-in-place at similar depths. The observed behaviour provided encouraging preliminary results and suggests that, with further development and analysis, the concept could potentially be used for commercial applications.
{"title":"An anchoring system for supporting platforms for wind energy devices","authors":"V. Sivakumar, J. Fanning, K. Gavin, S. Tripathy, A. Bradshaw, E. Murray, J. Black, S. Donohue","doi":"10.1680/jgeen.22.00245","DOIUrl":"https://doi.org/10.1680/jgeen.22.00245","url":null,"abstract":"This paper presents data from an initial development stage of an ‘umbrella anchor’ concept. The anchor can be pushed into sand deposit in a folded arrangement to reduce installation loads. When a pull-out load is applied to the mooring line, the anchor deploys to create a large embedded plate anchor. Physical modelling was carried out in saturated sand-bed with the anchor installed at depths of up to 1.6 m and loaded vertically. During installation, liquefaction was generated at the tip of the anchor to reduce the penetration resistance. This enabled the anchor to be installed quickly and accurately to a target depth. The anchor could provide pull-out resistances comparable to anchor that was wished-in-place at similar depths. The observed behaviour provided encouraging preliminary results and suggests that, with further development and analysis, the concept could potentially be used for commercial applications.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"119 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76933871","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}
Alexia Cindy Wagner, João Vítor de Azambuja Carvalho, João Paulo de Sousa Silva, H. C. Scheuermann Filho, N. Consoli
The disposal of iron ore tailings in dry stacks has become increasingly common in Brazil. In these structures, the iron ore tailings are compacted in layers using drum rollers that cause compaction and vibration efforts on the ground. Particle breakage is usually observed in granular materials when subjected to static loads of great magnitude, as can occur depending on the stacking height achieved. However, particle breakage also may occur during the layers’ compaction. This study investigates the breakage behaviour of iron ore tailings simulating load conditions that may occur during dry stacks construction. Two usual iron ore tailings with different amounts of clay size particles, but similar mineralogy (about 77% quartz and 19% iron oxide – the usual composition of iron ore tailings in Brazil) were subject to cyclic oedometer tests. Particle size distribution analyses were performed before and after testing all specimens. Both iron ore tailings, representing typical physical and mineralogical characteristics of the Quadrilátero Ferrífero (southeast Brazil), only suffered particle breakage (Relative Breakage between 0.12 and 0.14 for tailings A and between 0.14 and 0.16 for tailings B) under extremely high pressures (σ’v = 85 MPa) applied by oedometer testing, above those usually found in the field. For usual pressures applied in the field, the frequency of load and number of cycles were of no significance in particle breakage.
{"title":"Dry stacking of iron ore tailings: Possible particle breakage during compaction","authors":"Alexia Cindy Wagner, João Vítor de Azambuja Carvalho, João Paulo de Sousa Silva, H. C. Scheuermann Filho, N. Consoli","doi":"10.1680/jgeen.22.00216","DOIUrl":"https://doi.org/10.1680/jgeen.22.00216","url":null,"abstract":"The disposal of iron ore tailings in dry stacks has become increasingly common in Brazil. In these structures, the iron ore tailings are compacted in layers using drum rollers that cause compaction and vibration efforts on the ground. Particle breakage is usually observed in granular materials when subjected to static loads of great magnitude, as can occur depending on the stacking height achieved. However, particle breakage also may occur during the layers’ compaction. This study investigates the breakage behaviour of iron ore tailings simulating load conditions that may occur during dry stacks construction. Two usual iron ore tailings with different amounts of clay size particles, but similar mineralogy (about 77% quartz and 19% iron oxide – the usual composition of iron ore tailings in Brazil) were subject to cyclic oedometer tests. Particle size distribution analyses were performed before and after testing all specimens. Both iron ore tailings, representing typical physical and mineralogical characteristics of the Quadrilátero Ferrífero (southeast Brazil), only suffered particle breakage (Relative Breakage between 0.12 and 0.14 for tailings A and between 0.14 and 0.16 for tailings B) under extremely high pressures (σ’v = 85 MPa) applied by oedometer testing, above those usually found in the field. For usual pressures applied in the field, the frequency of load and number of cycles were of no significance in particle breakage.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"7 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83898054","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}
The performance of embedded retaining walls during and after excavation is commonly predicted using numerical techniques and assessed by field monitoring. However, subsequent back-analyses of post-construction monitoring data are rarely undertaken. The purpose of this paper is two-fold: (i) to provide a comprehensive post-construction review of site information and monitoring data from a construction site in central London and (ii) to detail results from a parametric study undertaken as part of the back-analyses of five key embedded retaining wall sections. The importance of accounting for the effects of non-linear soil stiffness when predicting wall deflection profiles is highlighted by the parametric study. Good agreement between the numerical model and field monitoring data was achieved through the back-analysis exercise. Differences in the predicted Class C wall deflection profiles are attributed to varying temporary support systems and complex 3D site geometry. Best practice recommendations relating to field monitoring and a new streamlined methodology for performing similar back-analyses are proposed.
{"title":"Back-analysis of an embedded retaining wall in stiff clay","authors":"Chuan Fong Foo, T. Le, Paul Bailie, J. Standing","doi":"10.1680/jgeen.22.00072","DOIUrl":"https://doi.org/10.1680/jgeen.22.00072","url":null,"abstract":"The performance of embedded retaining walls during and after excavation is commonly predicted using numerical techniques and assessed by field monitoring. However, subsequent back-analyses of post-construction monitoring data are rarely undertaken. The purpose of this paper is two-fold: (i) to provide a comprehensive post-construction review of site information and monitoring data from a construction site in central London and (ii) to detail results from a parametric study undertaken as part of the back-analyses of five key embedded retaining wall sections. The importance of accounting for the effects of non-linear soil stiffness when predicting wall deflection profiles is highlighted by the parametric study. Good agreement between the numerical model and field monitoring data was achieved through the back-analysis exercise. Differences in the predicted Class C wall deflection profiles are attributed to varying temporary support systems and complex 3D site geometry. Best practice recommendations relating to field monitoring and a new streamlined methodology for performing similar back-analyses are proposed.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"8 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81624895","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}
The problem of calculating the ultimate bearing capacity of screw pile has been studied by the limit equilibrium theory in this paper. The calculation methods of the critical screw pitch and the ultimate bearing capacity under two representative failure modes are proposed. Four key parameters affecting the ultimate bearing capacity are compared and analyzed, and the design optimization suggestions are put forward. The results illustrate that the ultimate bearing capacity of the screw pile is mainly affected by the shear strength of soil, the height of screw thread and the screw pitch. When designing the screw pile, the height of screw thread could be increased and the screw pitch reduced to some extent.
{"title":"Calculation method of bearing capacity of screw pile under compression load based on limit equilibrium theory","authors":"Jiakuan Ma, Rui Wang, Zhiping Hu, Tong Mu, Anlong Liu, Victor Tolulope Olusegun","doi":"10.1680/jgeen.22.00122","DOIUrl":"https://doi.org/10.1680/jgeen.22.00122","url":null,"abstract":"The problem of calculating the ultimate bearing capacity of screw pile has been studied by the limit equilibrium theory in this paper. The calculation methods of the critical screw pitch and the ultimate bearing capacity under two representative failure modes are proposed. Four key parameters affecting the ultimate bearing capacity are compared and analyzed, and the design optimization suggestions are put forward. The results illustrate that the ultimate bearing capacity of the screw pile is mainly affected by the shear strength of soil, the height of screw thread and the screw pitch. When designing the screw pile, the height of screw thread could be increased and the screw pitch reduced to some extent.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"3 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88060884","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}
Squeezing is a well-known geotechnical phenomena when excavating underground spaces, especially tunnels. It occurs under different geotechnical conditions in weak rock masses. A study was carried out to develop a mathematical and practical model to predict squeezing so that risk mitigation measures can be taken if necessary. A mathematical model based on the gene expression programming algorithm was developed using a database including 115 squeezing case histories. Four model performance evaluation criteria − specificity, sensitivity, accuracy and Matthew's correlation coefficient − were then used based on the test database and receiver operating characteristic curve. The accuracy of the model was also compared with previously developed models. The results showed that model can determine the squeezing with acceptable accuracy. It was then used to investigate squeezing-prone areas in the Beheshtabad water conveyance tunnel of Iran.
{"title":"Modelling tunnel squeezing using gene expression programming: a case study","authors":"M. Kadkhodaei, E. Ghasemi, Saeed Mahdavi","doi":"10.1680/jgeen.22.00151","DOIUrl":"https://doi.org/10.1680/jgeen.22.00151","url":null,"abstract":"Squeezing is a well-known geotechnical phenomena when excavating underground spaces, especially tunnels. It occurs under different geotechnical conditions in weak rock masses. A study was carried out to develop a mathematical and practical model to predict squeezing so that risk mitigation measures can be taken if necessary. A mathematical model based on the gene expression programming algorithm was developed using a database including 115 squeezing case histories. Four model performance evaluation criteria − specificity, sensitivity, accuracy and Matthew's correlation coefficient − were then used based on the test database and receiver operating characteristic curve. The accuracy of the model was also compared with previously developed models. The results showed that model can determine the squeezing with acceptable accuracy. It was then used to investigate squeezing-prone areas in the Beheshtabad water conveyance tunnel of Iran.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"356 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77159418","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}
Several investigations show that structures with rocking foundations bring more stability and fewer post-earthquake damages to superstructures by dissipating seismic energy within the underlying soils. Nevertheless, there are still obstacles to making this design philosophy a practical solution, including concerns about the residual settlements and rotations. In order to provide a better insight into the problem, the present paper investigates the performance of a simple structure with a rocking foundation, taking advantage of pushover and time history analyses. The finite element method is applied for the study, and the numerical model has been validated using results from recent experimental research. Accordingly, the effect of a number of influential parameters involving the properties of soil, structure, and ground motions is evaluated. Current research considers different static safety factors against soil shear strength failure, structure slenderness ratios, earthquake records, and foundation embedment depths, and the response of the systems with rocking foundations has been elaborated using the obtained results. The contribution of the investigated parameters is pronounced in the main features of the rocking foundation performance, such as the system moment capacity and foundation deformations (settlement and rotation).
{"title":"The numerical investigation of the main factors influencing rocking responses of shallow foundations","authors":"Seyed Omid Khamesi, S. M. Mir Mohammad Hosseini","doi":"10.1680/jgeen.22.00175","DOIUrl":"https://doi.org/10.1680/jgeen.22.00175","url":null,"abstract":"Several investigations show that structures with rocking foundations bring more stability and fewer post-earthquake damages to superstructures by dissipating seismic energy within the underlying soils. Nevertheless, there are still obstacles to making this design philosophy a practical solution, including concerns about the residual settlements and rotations. In order to provide a better insight into the problem, the present paper investigates the performance of a simple structure with a rocking foundation, taking advantage of pushover and time history analyses. The finite element method is applied for the study, and the numerical model has been validated using results from recent experimental research. Accordingly, the effect of a number of influential parameters involving the properties of soil, structure, and ground motions is evaluated. Current research considers different static safety factors against soil shear strength failure, structure slenderness ratios, earthquake records, and foundation embedment depths, and the response of the systems with rocking foundations has been elaborated using the obtained results. The contribution of the investigated parameters is pronounced in the main features of the rocking foundation performance, such as the system moment capacity and foundation deformations (settlement and rotation).","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"90 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84587819","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}
This paper reviews the load-settlement behaviour of 499 plate load tests of various diameters undertaken on granular soils and working platform materials to determine the angle of internal friction mobilised by the test. The observed settlement of individual plate load tests at relatively small settlement has been extrapolated to a theoretical failure of the plate at 10% and 15% of the plate's diameter (D). For each test an effective angle of internal shearing resistance was calculated based on the bearing resistance associated with the stress required to cause settlement of 0.10 or 0.15 times the plate diameter. The results are presented along with a discussion on the use of high friction materials in working platforms and shallow foundations. Characteristic values for the effective angle of internal shearing resistance are provided for all working platform materials tested as well as tests undertaken on platform materials comprising crushed brick and concrete. These values are compared to shear box test results on similar materials. Characteristic values of ϕ’ varying from 44° to 46.4° (0.1D) and 45.3° to 47.8° (0.15D) for crushed brick and concrete materials are calculated, which is slightly higher than that determined from tests on Type 1 material.
{"title":"Estimation of internal friction angle for working platform materials by plate load test","authors":"Burden Chitambira, Alastair Dewar","doi":"10.1680/jgeen.22.00248","DOIUrl":"https://doi.org/10.1680/jgeen.22.00248","url":null,"abstract":"This paper reviews the load-settlement behaviour of 499 plate load tests of various diameters undertaken on granular soils and working platform materials to determine the angle of internal friction mobilised by the test. The observed settlement of individual plate load tests at relatively small settlement has been extrapolated to a theoretical failure of the plate at 10% and 15% of the plate's diameter (D). For each test an effective angle of internal shearing resistance was calculated based on the bearing resistance associated with the stress required to cause settlement of 0.10 or 0.15 times the plate diameter. The results are presented along with a discussion on the use of high friction materials in working platforms and shallow foundations. Characteristic values for the effective angle of internal shearing resistance are provided for all working platform materials tested as well as tests undertaken on platform materials comprising crushed brick and concrete. These values are compared to shear box test results on similar materials. Characteristic values of ϕ’ varying from 44° to 46.4° (0.1D) and 45.3° to 47.8° (0.15D) for crushed brick and concrete materials are calculated, which is slightly higher than that determined from tests on Type 1 material.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"78 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74209542","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}
Dariush Mohammadi, K. Shahriar, P. Moarefvand, E. Farrokh
Among the various parts of the earth pressure balance (EPB) cutterheads, the opening distribution on the cutterhead face plays a crucial role in successful of the tunneling projects in soft grounds. However, the amount of published literature on this subject is very limited, as a result, tunnel boring machine (TBM) manufacturers have been developed different soft ground cutterheads with varied opening distributions through their experience. In this paper, at the first step, the field studies results for soft ground cutterheads opening design were expressed. Next, the paper mainly focused on the numerical studies using discrete element method (DEM) to evaluate the adaptability of the EPB system and cohesive and non-cohesive soils fluidity by changing the opening distribution on the cutterhead. Finally, the optimum opening ratio and its distribution for different soils by considering the value of the thrust force, cutterhead torque and soil fluidity condition as important parameters were proposed based on the analysis results from DEM accordingly. Furthermore, the flow characteristics of soil particles inside the EPB chamber was obtained through examination of velocity field, also the practical aspects with further application in TBM industry by considering field studies and a real example were discussed.
{"title":"Discussion of cutterhead opening design for earth pressure balance machines (EPBMs) in soft grounds","authors":"Dariush Mohammadi, K. Shahriar, P. Moarefvand, E. Farrokh","doi":"10.1680/jgeen.22.00254","DOIUrl":"https://doi.org/10.1680/jgeen.22.00254","url":null,"abstract":"Among the various parts of the earth pressure balance (EPB) cutterheads, the opening distribution on the cutterhead face plays a crucial role in successful of the tunneling projects in soft grounds. However, the amount of published literature on this subject is very limited, as a result, tunnel boring machine (TBM) manufacturers have been developed different soft ground cutterheads with varied opening distributions through their experience. In this paper, at the first step, the field studies results for soft ground cutterheads opening design were expressed. Next, the paper mainly focused on the numerical studies using discrete element method (DEM) to evaluate the adaptability of the EPB system and cohesive and non-cohesive soils fluidity by changing the opening distribution on the cutterhead. Finally, the optimum opening ratio and its distribution for different soils by considering the value of the thrust force, cutterhead torque and soil fluidity condition as important parameters were proposed based on the analysis results from DEM accordingly. Furthermore, the flow characteristics of soil particles inside the EPB chamber was obtained through examination of velocity field, also the practical aspects with further application in TBM industry by considering field studies and a real example were discussed.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"53 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77999968","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}
The pre-bored grouted planted (PGP) pile is a new type of composite pile, and the core PHC pile is surrounded by cemented soil layer. The frictional capacity of core PHC pile – cemented soil interface has a significant effect on the bearing capacity of PGP pile. A series of square pile (pipe pile) – soil interface shear tests were carried out in this study to study the frictional capacity of smooth square pile (pipe pile) – cemented soil interface. The shear test results show that the peak skin friction of square pile (pipe pile) – cemented soil interface both increased with the cemented soil strength; the peak skin friction of square pile – cemented soil interface was smaller than the peak skin friction of pipe pile – cemented soil interface of identical pile (equivalent) diameter, owing to the occurrence of stress concentration at the corners of square pile; the peak skin friction of square pile (pipe pile) – cemented soil interface both decreased with the pile (equivalent) diameter; the occurrence of cracks in the cemented soil caused the brittle failure of both square pile (pipe pile) – cemented soil interface.
{"title":"Laboratory tests on the frictional capacity of core pile – cemented soil interface","authors":"Jia-jin Zhou, Jianyuan Ren, Junqing Ma, Jian-lin Yu, Ri-hong Zhang, X. Gong","doi":"10.1680/jgeen.22.00205","DOIUrl":"https://doi.org/10.1680/jgeen.22.00205","url":null,"abstract":"The pre-bored grouted planted (PGP) pile is a new type of composite pile, and the core PHC pile is surrounded by cemented soil layer. The frictional capacity of core PHC pile – cemented soil interface has a significant effect on the bearing capacity of PGP pile. A series of square pile (pipe pile) – soil interface shear tests were carried out in this study to study the frictional capacity of smooth square pile (pipe pile) – cemented soil interface. The shear test results show that the peak skin friction of square pile (pipe pile) – cemented soil interface both increased with the cemented soil strength; the peak skin friction of square pile – cemented soil interface was smaller than the peak skin friction of pipe pile – cemented soil interface of identical pile (equivalent) diameter, owing to the occurrence of stress concentration at the corners of square pile; the peak skin friction of square pile (pipe pile) – cemented soil interface both decreased with the pile (equivalent) diameter; the occurrence of cracks in the cemented soil caused the brittle failure of both square pile (pipe pile) – cemented soil interface.","PeriodicalId":54572,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Geotechnical Engineering","volume":"467 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79883931","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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