Plugging is essential not only due to its direct contribution to pile end load carrying capacity but also due to its indirect contribution to mobilised shaft capacity. A pile with a plug displaces more soil than a pil...
Plugging is essential not only due to its direct contribution to pile end load carrying capacity but also due to its indirect contribution to mobilised shaft capacity. A pile with a plug displaces more soil than a pile that penetrates in boring mode, which enlarges the effective stresses around the pile. Numerical modelling of plugged pipe piles was carried out using PLAXIS-2015 software, with the Hardening Soil Model (HS small) used for soil modelling. The parametric study presented in this research was carried out with this computer program based on the finite element method. The case of a pipe pile group (2 × 2) with full plug was chosen as the basic problem, with spacing between piles of 3.0 m. It was concluded that there is slight increase in pile group capacity when increasing the spacing between piles by about 2.8%. It was found that the change of the angle of friction was the most important parameter; its increase from 31o to 40o caused an increase in the shear stress of about 150%.
This article uses finite element software to simulate the internal force and deformation of pile-soil under the wave and ice load. The group pile foundation model is simplified in the plane as a single pile affected b...
This article uses finite element software to simulate the internal force and deformation of pile-soil under the wave and ice load. The group pile foundation model is simplified in the plane as a single pile affected by other *** wave force based on Morison Equation,The effect of wave force and ice load calculated with the measured wave force and ice load on the pile is compared. According to the time history curve, when the absolute value of acceleration is maximum, the curves of the bending moment, axial force, shear and displacement of the pile with the depth of the pile under the action of wave force, ice load and joint force are analyzed, the time history curves of pile top displacement under the combined action of wave force and ice load are analyzed,the displacement time history curves of different positions of piles are ***, the effect of buried depth, pile diameter and free length on the pile body interaction under the wave force and ice load is analyzed.
A detailed understanding of particle crushing, which changes particle size distribution and influences the energy dissipation of broken rocks, is extremely important to underground engineering, such as the prevention ...
A detailed understanding of particle crushing, which changes particle size distribution and influences the energy dissipation of broken rocks, is extremely important to underground engineering, such as the prevention of dynamic hazards caused by hard roof. We have studied particle crushing and energy dissipation of the saturated broken gangue under variable axial stresses (2, 4, 8, 12 and 16 MPa). Testing results indicate that particle crushing was pervasive and mainly contained fracture, attrition and abrasion. 4 MPa was a critical axial stress for describing particle size distribution, compaction deformation and energy dissipation under compaction. Axial strain was an effective parameter to describe the particle crushing state. In general, both the axial strain and strain energy density were influenced by the initial gradation. A larger Talbot exponent corresponds to a larger axial strain and a smaller strain energy density.
Owing to progressively increased demands of high-strength steels (e.g. S460, S690 and S960) in steel construction, an experimental program was developed to study welded box-section steel columns under compression acco...
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A robust representation of hydrogeological properties of the examined study area in discretization step is essential in groundwater modelling to improve the accuracy and efficiency of the model. A number of studies ha...
A robust representation of hydrogeological properties of the examined study area in discretization step is essential in groundwater modelling to improve the accuracy and efficiency of the model. A number of studies have investigated the effect of grid cell size in model discretization using comparison of performances of different models representing different cell sizes. However, although grid size refinement effect on model performances was calculated, the impact of mean slope was not conclusively discussed. In this study, five models distinguished by five spatial discretization schemes; 10 x 10 m, 20 x 20 m, 30 x 30 m, 40 x 40 m and 50 x 50 m were constructed. Using PEST, hydraulic conductivity and specific yield values over a selection of pilot points were estimated. The effect of surface slope is discussed in order to recommend the most appropriate location for observation well placement in terms of topographical characteristic. It is confirmed that the deterioration of model performance is controlled by mean slope of the surface. Results reveal that model performance increases substantially for areas of low slope (< 3 %) and medium slope (3 ~ 10 %) for smaller a grid cell size. Therefore, to improve model performance, it is recommended that the observations wells are placed in areas of low and medium slopes.
作者：
Bibi M JacobS BincyPG Student
Structural Engineering and Construction Management St Josephs College of Engineering and Technology Assistant Professor
Dept. of Civil Engineering St. Joseph's College of Engineering and Technology Palai Kerala India
The main aim of this study is to investigate on the crack patterns and flexural strength of simply supported RC rectangular hollow beams and SFRC rectangular hollow beams (with a circular hole in longitudinal directio...
The main aim of this study is to investigate on the crack patterns and flexural strength of simply supported RC rectangular hollow beams and SFRC rectangular hollow beams (with a circular hole in longitudinal direction) under a loading frame with a gradual increasing load. The experimental program consists of casting and testing of 4RC and 4 SFRC beams of size 1400 × 150 × 150. M 25 grade of concrete was used for the casting of all the beams. Hollow beams were made using pipes of diameters 32mm, 40mm and 50mm and the position of placing the pipes are at a distance of 3 to 4 cm from bottom reinforcement. All other properties of the beam were kept constant such as the cross section of the beam and the amount of longitudinal steel. In this study we also focus on the material management by the introduction of a hollow core. By this material optimization we can decrease the dead loads which contributes to the seismic effect in high rise buildings. The influence of area of hole is taken as reference for the study. A comparison of experimental results of RC and SFRC were made to predict the crack behaviour and the flexural load carrying capacity of hollow beams.
For reducing indoor air pollution and controlling its effects, the method of sampling and experimental analysis is adopted. In addition, physical, chemical and microbial characteristics of the air conditioning system ...
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The fundamental requirement for the autonomous self-healing process to work is that cracks need to reach the capsules and cause to be *** all other aspects,the amount of healing agents released into the crack is essen...
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The fundamental requirement for the autonomous self-healing process to work is that cracks need to reach the capsules and cause to be *** all other aspects,the amount of healing agents released into the crack is essential to obtain a good *** the probability of crack intersection with capsules is critical in the development and design of stnictures made of capsule-based self-healing cementitious ***,from the perspective of the capsule shapes,spherical and elongated capsules(hollow tubes/fibres) are the main morphology of capsules used in the capsule-based self-healing *** focus of this contribution is the description of the effects of capsule shape on the efficiency of healing agent released in capsule-based self-healing cementitious material within the framework of the theory of geometrical *** models are developed to characterize the efficiency of healing agent released per crack area from capsules for an arbitrary crack intersecting with various shapes of capsules in a virtual capsule-based self-healing cementitious *** crack opening distance is chosen to be a key parameter in defining the healing potential of individual cracks in the ***,the reliabilities of the developed models can be verified by data from relevant literature information,which was implemented via numerical simulation.
Many vibration-based global damage detection methods attempt to extract modal parameters from vibration signals as the main structural features to detect damage. The local flexibility method is one promising method th...
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ISBN:
(纸本)9781605953304
Many vibration-based global damage detection methods attempt to extract modal parameters from vibration signals as the main structural features to detect damage. The local flexibility method is one promising method that requires only the first few fundamental modes to detect not only the location but also the extent of damage. Generally, the mode shapes in the lateral degree of freedom are extracted from lateral vibration signals and then used to detect damage for a beam structure. In this study, a new approach which employs the mode shapes in the rotary degree of freedom obtained from the macro-strain vibration signals to detect damage of a beam structure is proposed. In order to facilitate the application of mode shapes in the rotary degree of freedom for beam structures, the local flexibility method is modified and utilized. The proposed rotary approach is verified by numerical and experimental studies of simply supported beams. The results illustrate potential feasibility of the proposed new idea. Compared to the method that uses lateral measurements, the proposed rotary approach seems more robust to noise in the numerical cases considered. The sensor configuration could also be more flexible and customized for a beam structure. Primarily, the proposed approach seems more sensitive to damage when the damage is close to the supports of simply supported beams. The proposed approach also shows its potential application to damage detection of wind turbine blades and plate structures.
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