Effect of Existing Building Walls on the Geotechnical Behavior of Foundation under Earthquake Loading

2021 ◽  
Vol 6 (4) ◽  
pp. 100-104
Author(s):  
M. N. Massoud Elsiragy
Keyword(s):  
Large Scale ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Scale Model ◽  
Earthquake Loading ◽  
Three Dimensional Model ◽  
Foundation Soil ◽  
Soil System ◽  
Existing Building ◽  
Building Walls

— Structure’s systems are subjected to additional loads due to earthquakes that may be produces progressive failures. The building illustrates dissimilar categories of failure mechanism for the minor to major earthquake conditions. These structures categorized to the most susceptible type of building has experienced serious hazard or even full failure for the period of seismic activities, therefore their investigation is a complex thing to do. Consequently, this research aims at studying the behaviour of large-scale model of structures constructed with and without brick walls under seismic conditions. The effect of building walls on the performance of the structure during earthquake loading is investigated numerically using PLAXIS 3D software. An eight story building with basement designed on a mat foundation is simulated as three-dimensional model in case of brick walls existing and without brick walls case. The effect of existence such wall building on the stability of foundation soil system is discussed in the form of lateral, horizontal deformation, and foundation acceleration. The studied showed that the reduction of extreme horizontal displacement and bending moment for building foundation with brick walls reached to 43%, and 68% respectively compared to the building without walls. The consideration of wall as filling for super structure significantly reduce the foundation acceleration by as much as 72% of its initial value, which lead to considerable effect of increasing the foundation stability.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

scholarly journals Evaluation of Micropiles With Different Configuration Settings for Landslide Stabilization Based on Large-Scale Experimental Testing

2021 ◽  
Vol 9 ◽  
Author(s):  
Xueling Liu ◽  
Jinkai Yan ◽  
Bin Tong ◽  
Lei Liu
Keyword(s):  
Large Scale ◽  
Experimental Testing ◽  
Bending Moment ◽  
Scale Model ◽  
Sliding Surface ◽  
Double Row ◽  
Single Row ◽  
Pile Diameter ◽  
Negative Bending ◽  
Landslide Stabilization

In this study, a large-scale model test was performed to investigate the effect of the single-row and double-row micropiles on the landside stabilization. For two different testing configuration settings, the bending moment along the micropiles, failure mode, and force condition were captured and compared. It is found that the landslide thrust on piles was distributed in a triangular shape. The piles in the front row carried greater pressure than the piles in the rear row. The resistance of the sliding body behind the pile was distributed in a parabolic shape, and mainly concentrated on the middle of the pile. The piles were destroyed due to the combined shearing and bending impact applied near the slipping surface. The boundary of the failure zone was from the position of two times the pile diameter under the slipping surface to the position of two and a half times the pile diameter above the slipping surface. Under the action of the landslide, each row of piles deformed at the same time. The capability of landslide stabilization for double-row piles was better than that of a single-row pile. The sections of the pile above slide surface were mainly subjected to negative bending moments and were distributed mainly within the pile length range of one-third of the anti-sliding section above the sliding surface. The pile body of the embedded section located in the range of ten times the pile diameter below the sliding surface was subjected to a positive bending moment.

Analysis of the Frame Structure’s Force due to Subway Excavation with Different Horizontal Distance

2012 ◽  
Vol 170-173 ◽  
pp. 1437-1443
Author(s):  
Zhi Qiang Wu ◽  
Yong Li Hu ◽  
Yan Ping Lei
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Bending Moment ◽  
Scale Construction ◽  
Frame Structure ◽  
Horizontal Distance ◽  
Three Dimensional Model ◽  
Finite Element Software ◽  
Engineering Problems ◽  
Engineering Staff

With large-scale construction of subway lines, the influence of subway excavation to the frame structure has been an common problem to be solved. Finite element software was used to create three-dimensional model of the subway with different horizontal distance to the frame structure, and variation of frame structure’s bending moment, axial force, shearing force caused by subway excavation is obtained to analyze. The results will enable engineering staff to have a more comprehensive understanding on this issue, and provide guiding significance for solving similar engineering problems to some extent.

scholarly journals Experimental and Numerical Study of the Dynamic Response of XCC Pile–Raft Foundation under High-Speed Train Loads

2021 ◽  
Vol 11 (19) ◽  
pp. 9260
Author(s):  
Qiang Fu ◽  
Jie Yuan
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Large Scale ◽  
Numerical Study ◽  
Soft Soil ◽  
Composite Foundation ◽  
Scale Model ◽  
Vibration Velocity ◽  
Wheel Load ◽  
Foundation Soil

A series of dynamic large-scale model tests and three-dimensional finite element analyses were conducted to investigate the dynamic response of track embankment and XCC pile-raft composite foundation in soft soil for a ballastless high-speed railway under moving train loads. The results indicate that the vibration velocity obtained from the FE numerical simulation agrees well with that from the model test in vibration waveform, amplitude, and frequency characteristics. The peak values corresponding to the passing frequency of train carriage geometry (lc = 25 m), bogie (lab = 7.5 m), and axle distance (lwb = 2.5 m) respectively reflect the characteristic frequencies of the train compartment, adjacent bogie, and wheel load passing through. The peak velocity significantly depends on the distance from the track center in the horizontal direction, of which the attenuation follows the exponential curve distribution. The vibration velocities decrease rapidly within embankment, show a vibration enhancement region from raft to the 1 m depth of foundation soil, then decreases gradually along the subsoil foundation, to a very low level at the bottom of the subsoil, which is much lower than that at the track slab and roadbed. The pile-raft composite foundation can reduce the vibration level effectively and improve the safety of trains running in soft soil areas.

INVESTIGATING THE INTERACTION BETWEEN STABILIZED EXCAVATION BY NAILING AND ADJACENT URBAN TUNNELS: CASE STUDY

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Somaye Hosseini ◽  
Mahmood Parsaei
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Analysis Tool ◽  
Horizontal Distance ◽  
Subway Tunnel

Urban development could be evaluated by considering the transportation and construction industries. The transportation industry development causes an increase in the urban subway lines as well as underground tunnels. Concerning the construction industry, the large-scale buildings development such as commercial malls, high-rise buildings, and underground parking structures may require deep excavations at metropolitan projects. In this paper, a parametric study is carried out by considering the distance of a tunnel from a retaining wall with the staged construction. PLAXIS 2.0D ver.8.5 software is used as an analysis tool. The results show that existing tunnels are affected more than retaining walls during an excavation when the structural response is considered. By increasing the horizontal distance of tunnel center from the wall, lateral displacement and the bending moment of the tunnel would decrease 14% and the vertical displacement and bending moment of tunnel’s Crown would reduce by 15% and 12%, respectively. These interaction effects become negligible after a distance of 5 times the tunnel diameter. Besides, the existence of the tunnel in the vicinity of excavations would increase the top horizontal displacement of the retaining wall by about 13%. It is worthwhile to point out that the current paper is based on a case study on Sharif University multistory underground parking located near the subway tunnel in Tehran city stabilized by deploying a nailing and anchorage system.

Design and Make of a Segmented Ship Model for Vertical Bending Moment Measurement

2018 ◽  
Author(s):  
Jingxia Yue ◽  
Yulong Guo ◽  
Lihua Peng
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Bending Moment ◽  
Structural Safety ◽  
Scale Model ◽  
Wave Load ◽  
Scaled Model ◽  
Ship Model ◽  
Section Modulus ◽  
Vertical Bending Moment

With the development of the large-scale ship, the hull becomes more and more “soft” and “elastic”. Accurate simulation of ship’s hydro-elastic performance through scaled model test plays an important role in structural safety assessment. This paper presents the detail preparation of a segmented model which is used to investigate the vertical bending moment (VBM) for a 260m TEU container ship. Some innovative concepts were involved in the scaled model design. Firstly, the segmentation of the ship model was based on the hull’s vertical vibration mode for better simulation of the hull’s rigidity distribution. Secondly, the section of the backbone beam was varied by polishing along ship length in order to simulate the varied section modulus of ship hull. Thirdly, new backbone fixed type was carried out by two flange plates for a better wave load transmission. Besides, some useful techniques were provided, including the model making technique, calibration technique, and backbone system technique. It increases the feasibility of test, at a certain extent. Finally, an overview of the ongoing large scale model test plan and its future development directions is prospected.

scholarly journals Large-Scale Model Test of a Micropile Group for Landslide Control

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xueling Liu ◽  
Jinkai Yan ◽  
Lei Liu ◽  
Bing Han
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Bending Moment ◽  
Scale Model ◽  
Resistance Force ◽  
Bending Moments ◽  
Sliding Surface ◽  
Damage Area ◽  
Large Scale Model ◽  
Negative Bending

A large-scale model test on the interaction between a micropile group and a landslide was conducted, to investigate the effect of micropiles on the landsides prevention. The bearing mechanism, force condition, and failure mode of a micropile group for reinforcing landslide were analyzed in detail. The results showed that the thrust force over micropiles induced by landslide showed a trapezoidal distribution, with a higher Earth pressure near the sliding surface. The resistance from the sliding body behind the pile behaved in a parabolically trend. Meanwhile, the resistance force from the sliding bed was distributed unevenly along the height direction, with a higher resistance force near the sliding surface behind the pile. When a landslide occurred, micropiles were subjected to an increase in loading and displacement, eventually to the failure state. The load-bearing sections of the micropiles were all subjected to negative bending moments, with larger bending moments within the half length of pile range near the sliding surface. The maximum negative bending moment occurred at the height of seven times the diameter of the pile above the sliding surface. The damage mode along each row of micropiles was almost the same, showing a damage area within the range of three times the diameter of the pile above and below the sliding surface. The failure of micropile induced by landslides was mainly due to a combination effect of bending and shearing near the sliding surface.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

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