scholarly journals Lateral displacement under combined vacuum pressure and embankment loading

Géotechnique ◽  
2013 ◽  
Vol 63 (10) ◽  
pp. 842-856 ◽  
Author(s):  
J. CHAI ◽  
C.Y. ONG ◽  
J.P. CARTER ◽  
D.T. BERGADO
Keyword(s):  
Lateral Displacement ◽  
Vacuum Pressure

Vacuum consolidation and its combination with embankment loading

2006 ◽  
Vol 43 (10) ◽  
pp. 985-996 ◽  
Author(s):  
J -C Chai ◽  
J P Carter ◽  
S Hayashi
Keyword(s):  
Penetration Depth ◽  
Lateral Displacement ◽  
Fem Analysis ◽  
Field Measurements ◽  
Numerical Approach ◽  
Vacuum Pressure ◽  
Construction Time ◽  
Vacuum Consolidation ◽  
Prefabricated Vertical Drains ◽  
Prefabricated Vertical Drain

A method is proposed for determining the optimum penetration depth of prefabricated vertical drains (PVDs) in cases where vacuum consolidation is combined with the use of PVDs in a clayey deposit with two-way drainage. The advantages of combining vacuum pressure with embankment loading are discussed in terms of reducing preloading-induced lateral displacement of the subsoil, increasing the effective surcharge loading, and reducing construction time in the case of road construction. A vacuum consolidation project conducted in Saga, Japan, is described, and the results from a fully instrumented test section are presented and analyzed using a two-dimensional finite element approach. The numerical simulations compare well with the field measurements. The validated numerical approach is then used to examine the response of soft subsoil subjected to vacuum consolidation. The results confirm the usefulness of the proposed method for determining the optimum penetration depth of PVDs and the advantages of combining vacuum pressure with embankment loading.Key words: vacuum consolidation, preloading, prefabricated vertical drain, FEM analysis, embankment.

scholarly journals Estimation of Influence Scope of Lateral Displacement of Soft Ground under Vacuum Pressure with PVD

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jingyun Liu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
Yuanqiang Cai ◽  
Xiuqing Hu
Keyword(s):  
Clayey Soil ◽  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Vacuum Pressure ◽  
Vacuum Preloading ◽  
Treated Area ◽  
Prefabricated Vertical Drain ◽  
Soil Foundation ◽  
Soft Soil Foundation

The application of vacuum pressure to a treated area not only induces vertical settlement and inward lateral displacement but also causes the formation of tension cracks near the ground surface. In general, the strain method is applied to calculate the lateral displacement at the boundary of a treated area; however, the influence scope of lateral displacement has not yet been presented. Based on the in situ data of soft clayey soil foundation treated by vacuum consolidation, lateral displacement was estimated in the influence scope in this study. To calculate the influence scope of lateral displacement induced by vacuum pressure, the ratio of the lateral displacement within the influence scope to the ground surface settlement under the centre of the treated area is defined as the maximum value of the lateral displacement (ELD) within the influence scope. This paper proposes a direct relationship between ELD and the distance from the treated area boundary (Lx), considering the length of the prefabricated vertical drain. In addition, the FEA (finite-element analysis) is used to simulate the process of vacuum preloading to reinforce soft soil foundation. The influence scope simulated is almost close to the calculated value Lx. Accordingly, the safety distance between the boundary of the treated area and the surrounding building can be estimated when the soft soil foundation is consolidated by using a vacuum preloading method.

Method and results of experimental researches of modes of work of the adaptive milking equipment on the basis of the portion meter of the weight type

2020 ◽  
pp. 140-146
Author(s):  
I. A. Afanasiev ◽  
V. V. Tkach
Keyword(s):  
Regression Analysis ◽  
Vacuum Pressure ◽  
Limit Values ◽  
Operating Modes ◽  
Machine Milking ◽  
Milk Output ◽  
Mode Of Operation ◽  
Milking Machine ◽  
Experimental Researches

Annotation Purpose. Improving the efficiency of machine milking due to the improvement of milking equipment on the basis of the portion meter of the weight type. Methods. Studies have been conducted on the basis of the planned experiment. The data obtained were processed using the methods of regression analysis. Results. The technique of laboratory researches is developed, a prototype of a membrane regulator of vacuum is made and experimental researches of operating modes of the adaptive milking equipment on the basis of the portion meter of the weight type. According to the results of the research, the dependence between the parameters and the mode of operation of the membrane vacuum regulator was obtained. Conclusions. The dependence is obtained, between the vacuum pressure in the milk collection chamber of the collector, milk expense, the diameters of the milk pipe and the diameters of a throttle opening. The limit values of the intensity of milk output (0.2 m3/s) at which there is a critical drop in the working vacuum pressure in the milk collection chamber of the collector and the corresponding choke parameters (diameter of the throttle opening 0,001 m) are defined. This eliminates this negative phenomenon. Keywords: adaptive milking equipment, milking machine, machine milking, milk expense.

Optimization of the operational parameters of a picking-type pneumatic planter using response surface methodology

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
SK PATEL ◽  
JB BHIMANI ◽  
P GUPTA ◽  
BK YADUVANSHI
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Important Variable ◽  
Vacuum Pressure ◽  
Forward Speed ◽  
Operational Parameters ◽  
Seed Spacing ◽  
Lady’S Finger ◽  
Multiple Regression Technique ◽  
Seed Metering Device

Singulation of seeds has been investigated extensively by researchers all over the world and a large number of precision seeding systems with design variations have been developed for different crops. A picking type metering mechanism was developed at CAET, AAU, Godhra, Gujarat, India. The performance of the picking type seed-metering device of a pneumatic planter was investigated under laboratory conditions to optimize the operating parameters for lady's finger seed. The picking of single seed the three operational parameters i.e. hole diameters for the nozzle: 1.0, 1.5, 2.5 and 3.0 mm; forward speed: 0.37, 0.56, 0.83, 1.11 and 1.30 m/s and vacuum pressure: 19.33, 39.32, 43.98, 58.64 and 68.63 kPa were selected for the study. The metering system of the planter was set to place the seed to seed spacing at 300 mm. The response surface methodology (RSM) technique was used to optimize the operational parameters of a precision planter. For optimizing the forward speed, vacuum pressure and nozzle size for developed machine was evaluated by examining the miss index, multiple index, quality of feed index and precision. The data obtained in the experiments were used to develop functions in polynomial form using multiple regression technique. The optimum value was found to be around 0.96 m/s, 36.25 kPa and 2.0 mm of forward speed, vacuum pressure and the holes diameter of nozzle, respectively. The most important variable that governs planting phenomenon is the combination of hole diameter of nozzle and vacuum pressure accounts 89.18 per cent.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Three-Axis Pneumatic Haptic Display for the Mechanical and Thermal Stimulation of a Human Finger Pad

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 60
Author(s):  
Eun-Hyuk Lee ◽  
Sang-Hoon Kim ◽  
Kwang-Seok Yun
Keyword(s):  
Pulse Width Modulation ◽  
Haptic Feedback ◽  
Control Function ◽  
Lateral Displacement ◽  
Gain Control ◽  
Haptic Display ◽  
Positional Accuracy ◽  
Control Module ◽  
Haptic Displays ◽  
Human Finger

Haptic displays have been developed to provide operators with rich tactile information using simple structures. In this study, a three-axis tactile actuator capable of thermal display was developed to deliver tactile senses more realistically and intuitively. The proposed haptic display uses pneumatic pressure to provide shear and normal tactile pressure through an inflation of the balloons inherent in the device. The device provides a lateral displacement of ±1.5 mm for shear haptic feedback and a vertical inflation of the balloon of up to 3.7 mm for normal haptic feedback. It is designed to deliver thermal feedback to the operator through the attachment of a heater to the finger stage of the device, in addition to mechanical haptic feedback. A custom-designed control module is employed to generate appropriate haptic feedback by computing signals from sensors or control computers. This control module has a manual gain control function to compensate for the force exerted on the device by the user’s fingers. Experimental results showed that it could improve the positional accuracy and linearity of the device and minimize hysteresis phenomena. The temperature of the device could be controlled by a pulse-width modulation signal from room temperature to 90 °C. Psychophysical experiments show that cognitive accuracy is affected by gain, and temperature is not significantly affected.

Lateral obstacle avoidance control based on driving behavior recognition of the preceding vehicles in adjacent lanes

2020 ◽  
Vol 68 (10) ◽  
pp. 880-892
Author(s):  
Youguo He ◽  
Xing Gong ◽  
Chaochun Yuan ◽  
Jie Shen ◽  
Yingkui Du
Keyword(s):  
Obstacle Avoidance ◽  
Lateral Displacement ◽  
Longitudinal Velocity ◽  
Driving Behavior ◽  
Lateral Acceleration ◽  
Lateral Motion ◽  
Behavior Recognition ◽  
Dynamic Surface ◽  
Lane Changing ◽  
The Impact

AbstractThis paper proposes a lateral lane change obstacle avoidance constraint control simulation algorithm based on the driving behavior recognition of the preceding vehicles in adjacent lanes. Firstly, the driving behavior of the preceding vehicles is recognized based on the Hidden Markov Model, this research uses longitudinal velocity, lateral displacement and lateral velocity as the optimal observation signals to recognize the driving behaviors including lane-keeping, left-lane-changing or right-lane-changing; Secondly, through the simulation of the dangerous cutting-in behavior of the preceding vehicles in adjacent lanes, this paper calculates the ideal front wheel steering angle according to the designed lateral acceleration in the process of obstacle avoidance, designs the vehicle lateral motion controller by combining the backstepping and Dynamic Surface Control, and the safety boundary of the lateral motion is constrained based on the Barrier Lyapunov Function; Finally, simulation model is built, and the simulation results show that the designed controller has good performance. This active safety technology effectively reduces the impact on the autonomous vehicle safety when the preceding vehicle suddenly cuts into the lane.

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