scholarly journals SINGLE PILES SETTLEMENT UNDER THE ACTION OF NEGATIVE FRICTION FORCES

2017 ◽  
Vol 2 (49) ◽  
pp. 171-176
Author(s):  
O. V. Samorodov ◽  
D. L. Muliar ◽  
S. V. Tabachnikov
Keyword(s):  
Experimental Data ◽  
Pile Foundation ◽  
Reliable Method ◽  
Field Testing ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Actual Load ◽  
Single Piles ◽  
Negative Friction ◽  
Full Scale Tests

Nowadays, the use of pile-plate foundations has received extensive development, which takes into account the soil inclusion in the work under its plate part. We proposed a new design of a plate-pile foundation and an engineering method for determining the main parameters of such a foundation, where one of the parameters is the piles settlement under the action of the negative friction forces Pn. As far as is known, field testing of production piles using pressing-in loads is the most reliable method for determining their actual load-bearing capacity. We carried out full-scale tests of a multi-section pile with the loading at depth, on the basis of which a comparative analysis of the settlement of single piles from the action of the negative friction forces, obtained with the help of adapted and existing methods and experimental data

scholarly journals Applying the dimensional method for valuation of the strength loss of cement compositions exposed to elevated temperatures

2018 ◽  
Vol 251 ◽  
pp. 02005
Author(s):  
Nikita Levashov ◽  
Marina Akulova ◽  
Olga Potemkina ◽  
Alla Sokolova ◽  
Yulia Sokolova
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Elevated Temperatures ◽  
Classical Method ◽  
Strength Loss ◽  
Ultimate State ◽  
Load Bearing Capacity ◽  
Full Scale Tests ◽  
Loss Of Strength

The paper presents the basis of the analytical model for calcu-lating the loss of strength in ce-ment compositions exposed to elevated temperatures. This model is to replace the classical method of calculating the fire resistance of the loss of load-bearing capacity. The experimental data were taken as initial indicators. Based on the implemented calculations it would become possible to predict the occurrence of ultimate state by loss strength and the reliability of practical indicators obtained by means of full-scale tests

scholarly journals LABORATORY EXPERIMENTAL RESEARCH OF LOADING FORCES DEVELOPMENT ACTING ON THE SIDE SURFACE OF THE PILES

2018 ◽  
Vol 1 (50) ◽  
pp. 174-180
Author(s):  
V. E. Naydenova
Keyword(s):  
Experimental Research ◽  
Lateral Surface ◽  
Side Surface ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Ground Resistance ◽  
Theoretical Statement ◽  
Torque Load ◽  
Negative Friction ◽  
Resistance Forces

The forces of negative friction or loading forces of friction on the piles develop due to additional deformations of near pile array and they cannot be more force of resistance on the side of pile in rest, that is formed due to own weight of the ground founding. The paper presents the results of laboratory experimental research of loading forces of friction acting on the lateral surface of the piles without taking into account the vertical load (being relatively at rest) and provided an analysis of methods for detection of negative friction forces (loading forces) acting on the lateral surface of the pile, with the appointment of their load-bearing capacity. The researches have confirmed the theoretical statement about the equality of the loading forces of friction to ground resistance forces under the action of the torque load but not the pulling load, as it is suggested in the modern standards.

Increasing the capacity of an extended nutrient removal plant by using different techniques

1998 ◽  
Vol 37 (9) ◽  
pp. 175-183 ◽  
Author(s):  
B. Andersson ◽  
H. Aspegren ◽  
U. Nyberg ◽  
J. la Cour Jansen ◽  
H. Ødegaard
Keyword(s):  
Nitrogen Concentration ◽  
Treatment Plant ◽  
Appropriate Technology ◽  
Secondary Effluent ◽  
Suggested Approach ◽  
Future Design ◽  
Actual Load ◽  
Full Scale Tests ◽  
Plant Capacity ◽  
Treatment Step

A comprehensive investigation which included full scale tests was initiated towards the late 1980:s with the primary aim to find an appropriate technology for the Klagshamn wastewater treatment plant in Malmö, Sweden. The finally selected strategy enabled that a concentration of less than 8 mg N/l could be reached in the secondary effluent without having to extend either the primary or secondary treatment step at the actual load on the plant. In order to comply with a future stringent phosphorus standard however, a tertiary filtration plant has to be built. In future, it has to be anticipated that the load on the plant may be doubled due to the fact that a bridge between Malmö and Copenhagen is being built. As a consequence, it was important to continue the upgrading work by estimating the ultimate plant capacity and to look for measures to increase the capacity if necessary. By optimising the plant operation, it seems possible to reach an effluent nitrogen concentration of less than 12 mg/l at a load corresponding to the future design load. The suggested approach implies that the plant has to be operated on the margin and as a consequence the possibility to include a denitrification step as part of the filtration plant was also investigated. As a result, it was decided to build a separate denitrification step at the same time as the filtration plant was built.

scholarly journals The Roball

2002 ◽  
Vol 35 (3) ◽  
pp. 204-207 ◽  
Author(s):  
William H. Robinson
Keyword(s):  
Seismic Isolation ◽  
Inverted Pendulum ◽  
Experimental Results ◽  
Flat Plates ◽  
Isolation System ◽  
Friction Forces ◽  
New Device ◽  
System A ◽  
Full Scale Tests ◽  
User Friendly

Robinson Seismic's latest developments in seismic isolation includes a new device, the RoballTM, for seismically isolating structures during earthquakes. This advance is a new concept for seismic isolation based on the principle of the inverted pendulum. It consists of 'friction balls' or 'Roballs' moving between upper and lower spherical like cavities or flat plates. The Roballs are filled with a material which is able to provide the friction forces required to absorb the energy from numerous earthquakes while supporting the structure. The Roball technique is expected to enable light and in the future possibly heavy structures to be more economically seismically isolated. As part of a program to develop a user friendly 'seismic isolation system' a series of full-scale tests have been carried out on a number of possible designs including three approaches for vertical pressures of -1 MPa resulting in coefficients of friction of -0.1 to -0.4. In this paper we present the preliminary experimental results.

Buildings on the Slope Considering Effects of Uneven Settlement of Single Pile on the Structure Research

2011 ◽  
Vol 368-373 ◽  
pp. 1949-1954
Author(s):  
Li Ming Wu ◽  
Zi Jian Wang
Keyword(s):  
Finite Element Analysis ◽  
Pile Foundation ◽  
Normal Load ◽  
Single Pile ◽  
Analysis Software ◽  
Load Bearing Capacity ◽  
Element Analysis ◽  
Structural Impact ◽  
Different Parts ◽  
Structure Research

Buildings built on the slope and slope, in order to avoid a lot of digging embankment. According to the slope of potential changes in pile foundation of General unequal height. In the design of such buildings are generally the superstructure and Foundation when considered separately, under normal load bearing capacity and deformation is to meet to coordinal requirements.Changes in water level cause of slope sliding, so lead to individual settlement, the class meets the deformation of the structure of coordination of the Department of architecture and how the force is not known. Based on this, to a shore in 8 layers of pile foundation in the framework, for example, using finite element analysis software ANSYS in different parts of a single settlement on the basis of structural impact.

An Investigation of Air-Cooled Steam Condenser Performance Under Windy Conditions Using Computational Fluid Dynamics

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
M. T. F. Owen ◽  
D. G. Kröger
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Performance Evaluation ◽  
Test Data ◽  
Reliable Method ◽  
Numerical Results ◽  
Pressure Jump ◽  
Fan Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Full Scale Tests

The development of an efficient and reliable method of evaluating the performance of an air-cooled steam condenser (ACC) under windy conditions using computational fluid dynamics (CFD) is presented. A two-step modeling approach is employed as a result of computational limitations. The numerical ACC model developed in this study makes use of the pressure jump fan model, among other approximations, in an attempt to minimize the computational expense of the performance evaluation. The accuracy of the numerical model is verified through a comparison of the numerical results to test data collected during full-scale tests carried out on an operational ACC. Good correlation is achieved between the numerical results and test data. The effect of wind on ACC performance at El Dorado Power Plant (Nevada, USA) is investigated. It is found that reduced fan performance due to distorted flow at the inlet of the upstream fans is the primary contributor to the reduction in ACC performance associated with increased wind speed in this case. The model developed in this study has the potential to allow for the evaluation of large ACC installations and provides a reliable platform from which further investigations into improving ACC performance under windy conditions can be carried out.

Head Curve of Noncavitating Inducer

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Wen-Guang Li
Keyword(s):  
Experimental Data ◽  
Correction Factor ◽  
Reliable Method ◽  
Hydraulic Loss ◽  
Blade Angle ◽  
Singularity Method ◽  
Blade Thickness ◽  
Hydraulic Design ◽  
The Mean ◽  
Good Agreement

In the inducer hydraulic design, one significantly important task is to estimate its noncavtating head; however, there is not a matured and reliable method for this presently. In this paper, a method was made for predicting the inducer head curve. The method was based on a singularity method and a hydraulic loss model with a variable correction factor. The blade thickness blockage effect on the flow was taken into account. The method was validated with the experimental data of the existing 17 inducers found in references. Moreover, the curves showing the relation of the correction factor with the mean blade angle at tip for two- and three-bladed inducers were established. The method can achieve a very good agreement with experimental observations. Furthermore, the flow field calculated by the method may be instructive to the engineers of inducer hydraulic design.

scholarly journals Application of Ground Penetrating Radar in Detecting Deeply Embedded Reinforcing Bars in Pile Foundation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Daochuan Zhou ◽  
Haitang Zhu
Keyword(s):  
Ground Penetrating Radar ◽  
Pile Foundation ◽  
Field Testing ◽  
Radar Image ◽  
Reinforcing Bars ◽  
Raw Data ◽  
Centre Frequency ◽  
Wave Interference ◽  
Concrete Pile ◽  
Ground Penetrating

Ground penetrating radar (GPR) has been widely used for nondestructive testings in civil engineering. However, the GPR has not been adequately applied in detecting deeply embedded reinforcing bars, which is usually difficult to be revealed in radar image due to the wave interference and attenuation in large depth penetration. This study presents a new approach for the GPR detection of deeply embedded reinforcing bars in the reinforced concrete pile foundation. The aim of the GPR survey is to determine the existence and the depth of internal reinforcing bars in the pile foundation for solving engineering dispute. Low centre frequency antenna was used in GPR field testing to obtain the reflected raw data. Optimized procedures of digital filtering techniques were applied to process the GPR raw data. The deeply embedded reinforcing bars are revealed in the radar image after the field testing and postprocessing procedures. The depth of the reinforcing bars was estimated based on the hyperbola match method. The GPR test results were validated by the excavation of the pile foundation. The low centre frequency antenna has been found to be essential to obtain the reflected wave signals of deeply embedded reinforcing bars. The optimized processing procedures is useful to identify and display the reinforcing bars in radar image. The combination of low centre frequency antenna and the postprocessing procedures make the detection of deeply embedded reinforcing bars feasible. The proposed GPR testing method has been found to be effective to estimate the depth of deeply embedded reinforcing bars, which provides the key information for solving engineering dispute.

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