Abstract
In the present study, bending and free vibration analyses of a micro annular plate with piezomagnetic layers are investigated based on FSDT in the presence of magnetic field and resting on the elastic foundation. The multi-field constitutive relations are developed using modified strain gradient theory and the equilibrium governing equations of motion micro annular plate are derived using minimum of total potential energy and Hamilton's principles. One can arrive at numerical results using the semi analytical solution procedure. The Ritz method is used to obtain the results in the parametric state. The boundary conditions are applied to guess the primary functions and the minimization is used to obtain the unknown coefficients in the assumed solution. The effect of micro parameter, various geometric parameter and the foundation parameter is studied on the dynamic and static responses.
Key Words
functionally graded materials; modified strain gradient theory; piezomagnetic; ritz approach; shear deformation theory
Address
Defang Chen and Weiwei Wang: College of Sports and Health, Nanchang Institute of Science & Technology, Nanchang 330108, Jiangxi, China
H. Elhosiny Ali: Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
Amjad S. Qazaq: Department of Civil Engineering, College of Engineering in Al-Kharj, Prince Sattam Bin Abdulaziz University,
Al-Kharj, 11942, Saudi Arabia
Minghui Long: College of management, Wuhan Donghu University, Wuhan 430072, Hubei, China
Abstract
The spatial size effect (SSE) of the broken-expansion mass is crucial in mining engineering, particularly with the promotion of the 110/N00 mining method. We analyzed the broken-expansion characteristics of bulking mass and introduced the space ratio and SSE coefficient to understand the SSE of broken-expansion mass. The results and analyses show a clear SSE in broken-expansion mass, and the suggested space ratio can be utilized to describe SSE. When the space ratio increases, the initial (KI) and residual (KR) broken-expansion factors increase, and the greater the space ratio, the more rapidly the increase. KI generally determines KR, but the compression inhibits SSE. The proposed SSE coefficient can express the SSE and the inhibition. Additionally, the SEE coefficient explains the SSE differentiation in the displacement characteristics. A larger space ratio leads to a greater volume reduction. Meanwhile, the bulking samples show a growing compressive capacity, and it can benefit from a smaller accumulation area. Compression failure in bulking mass is a dynamic process where structures change from loose to firm. The upper samples fail and fill voids, and the lower samples adjust positions to prevent failure. Finally, the discussion suggests the implications to the 110/N00 mining method.
Address
Pengfei Guo, Yongxu Zhao, Shiwei Deng,iaoyun Zhang, Haijiang Zhang and Zhikang Li: Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province, School of Civil Engineering,
Shaoxing University, Shaoxing 312000, China
Xingyu Zhang: Faculty of Geo-Data Science, Geodesy and Environmental Engineering, AGH University of Science and Technology,
Krakow 30-059, Poland
Manchao He: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology,
Beijing 100083, China
Abstract
Anchor foundation systems are widely used to withstand uplift or pullout loads. Structures like tall buildings, transmission towers, jetty structures etc. experience such loads which can hinder the stability of the structure. Plate anchors develop resistance from the imposed soil weight and the shear stress along the failure surfaces formed during pullout, as the plate experiences the pullout load. Thus, the pullout load is resisted. The paper studies the pullout behavior of plate anchor using extensive laboratory model tests. The effect of different sizes of plate anchors, their embedment and different position of reinforcement on the pullout behavior have been studied. Different non-dimensional parameters have been used to represent the pullout behavior and the improvement in pullout capacity. Further, this study aims to identify the enhancement of pullout capacity over unreinforced soil due to the inclusion of reinforcement. For this, a parametric study has been carried out by conducting pullout tests with model square, rectangular and strip anchors embedded in unreinforced and reinforced soil made up of artificially prepared compacted Kaolin as clay bed. The outcomes have been presented in different non-dimensional form, such as: embedment ratio (H/B), relative depth of reinforcement (H/H), size of plate (L/B), and relative ultimate displacement (Su/B), and the influence of different parameters has been studied. Breakout factors for anchors of different sizes have been obtained from the ultimate pullout loads for both reinforced and unreinforced soil. Pullout capacity of plate anchors gets increased due to geotextile reinforcement in the embedded soil irrespective of depth of embedment of anchors. Considering all the parameters used in the present study such increase is about 47 to 63% in cases of square and rectangular anchors compared to 36% in strip anchor. Further, the position of geotextile also significantly influences the pullout behavior of anchor. Maximum increase in pullout load is achieved for reinforcement nearer to the plate.
Address
Narayan Roy: Department of Civil Engineering, Jadavpur University, Kolkata, India
Sibapriya Mukherjee: Department of Civil Engineering, Narula Institute of Technology, Agarpara, Kolkata, India
Ambarish Ghosh: Department of Civil Engineering, Indian Institute of Engineering Science and Technology (IIEST), Shibpur, India
Abstract
This paper conducted in-situ horizontal load tests on rectangular piles both before and after grouting and systematically analyzed the data. Firstly, the typical response characteristics of rectangular piles in gravelly soil under horizontal loading were determined. Secondly, a set of p-y curve models applicable to rectangular section piles was constructed by utilizing hyperbolic equations combined with the in-situ shear strength parameters and deformation parameters of the soil. Finally, based on the constructed p-y curve models, various important factors determining the response of rectangular piles under horizontal loading were analyzed in detail.
Key Words
field test; gravelly soil; p-y curves; rectangular pile; ultimate lateral resistance
Address
Wenshuai Li, Weiming Gong and Guoliang Dai: School of Civil Engineering, Southeast University, Nanjing 211189, China
Abstract
Functionally graded carbon nanotubes-reinforced composite (FG-CNTRC) has demonstrated a substantial promise for developing advanced lightweight structures and multifunctional composites, a crucial part of modern life, such as in the automotive, aerospace, marine, and medical industries. This work investigates the wave propagation behavior of FG-CNTRC beams resting on an elastic foundation with four configuration patterns of single-walled carbon nanotubes (SWCNTs). The key innovations in this study include nonlinear distributions of FG-CNTs based on exponential power-law models to achieve an optimal distribution of CNTs within the matrix, a Kerr substrate to illustrate the impact of the surroundings, and an improved integral first-order shear deformation theory (FSDT) to analytically formulate the dispersion of the waves with a novel correction function describing the distribution of shear stresses and strains. The rule of mixture is employed in estimating the elastic material's properties, and the governing equations of motion are derived using Hamilton's principle. The results are compared to those found in the literature for validation of the models. The parametric investigation includes the influence of the CNT's dispersion patterns and volume fraction on wave propagation responses. In addition, the study examines the effects of the Kerr foundation and the nonlinear models on wave dispersion behavior. Analytical findings suggest that the arrangements of CNTs manipulate the rigidities of the beams, affecting the dispersion relations. Also, increasing the volume fractions of CNTs improves the stiffness of the beams, corresponding to faster wave velocities. Further, the nonlinear distributions of FG-CNTs greatly influence the wave propagation, depending on the wave type and the patterns of CNTs. Moreover, the foundation presence boosts wave velocities and influences only the bending waves.
Key Words
carbon-nanotube; functionally graded beams; integral first order; Kerr foundation; nonlinear distribution; shear theory; wave propagation
Address
Saeed Al-Houri, Qais Gawah and Salah U. Al-Dulaijan1: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals,
31261 Dhahran, Eastern Province, Saudi Arabia
Mohammed A. Al-Osta: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals,
31261 Dhahran, Eastern Province, Saudi Arabia;
Interdisciplinary Research Center for Construction and Building Materials, KFUPM, 31261 Dhahran, Saudi Arabia
Fouad Bourada: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Department of Civil Engineering, Algeria
Abdelouahed Tounsi: Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals,
31261 Dhahran, Eastern Province, Saudi Arabia;
Interdisciplinary Research Center for Construction and Building Materials, KFUPM, 31261 Dhahran, Saudi Arabia;
Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Department of Civil Engineering, Algeria
Abdeldjebbar Tounsi: Department of Mechanical Engineering, Faculty of Science and Technology, University of Rélizane, Algeria
Abstract
The stepped reinforcement arrangement in mechanically stabilized earth (MSE) walls is more complicated than the common uniform arrangement design.Afinite element limit analysis (FELA) method combining the advantages of finite element (FE) and limit analysis (LA) methods was used to investigate the influence of stepped reinforcement arrangements on the seismic stability of MSE subjected to vertical and horizontal earthquakes. The pseudo-static FELA method was validated against results from model tests and the limit equilibrium-based (LE) method. The validated numerical model was then used to investigate the seismic stability and failure mechanisms of MSE walls with stepped reinforcement arrangements. Results indicate that multiple slip planes form in reinforced zone and backfills. The stepped reinforcement arrangement can help improve seismic stability. However, excessive increases in reinforcement length toward the top of the wall could have a negative influence on seismic stability, especially in cases of walls with wide reinforcement spacing.
Key Words
failure mechanism; finite element limit analysis; MSE walls; seismic stability; stepped reinforcement arrangement
Address
Weichao Liu and Guangqing Yang: Department of Civil Engineering, Shijiazhuang Tiedao University, 17 Northeast Second Inner Ring, China
Peng Xu: State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures, Shijiazhuang Tiedao University,
17 Northeast Second Inner Ring, China
Miren Rong: School of Urban Geology and Engineering, Hebei GEO University, No. 136 East Huai'an Road, Yuhua Distirict, China
Abstract
The soil layers in the site of Pars Service Port (PSP) have significant risks of liquefaction due to seismic activity. In order to mitigate the liquefaction hazards, Dynamic Compaction (DC) method as a cost-effective solution has been employed. Hence, by comparing a probabilistic assessment of liquefaction hazards before and after DC at PSP using fragility functions, the effectiveness of DC in the reduction of liquefaction hazards can be quantified. In fact, the fragility analysis and assessment for liquefiable sites have not been paid enough attention to. This study focuses on the liquefaction possibility of PSP at the seismic levels through liquefaction risk maps before and after DC. Risk maps play a crucial role in determining land use and reducing the vulnerability of structures and sites. Examining the liquefaction risk maps of PSP enables proactive measures to prevent the construction of high-importance structures in areas with a moderate, high, or severe exceedance probability of liquefaction. This approach helps to avoid potential risks and ensures that construction projects are carried out in safer locations.
Address
Mahdieh Afshari: Department of Civil Engineering, University of Science and Culture, Tehran, Iran
Hamid Alielahi: Department of Civil Engineering, Zanjan Branch, Islamic Azad University, Zanjan, Iran
