scholarly journals Analysis Of Dynamic Replacement Column Construction Process On Neighbouring Engineering Structures

2015 ◽  
Vol 61 (3) ◽  
pp. 3-18
Author(s):  
M. Łupieżowiec ◽  
P. Kanty
Keyword(s):  
Numerical Model ◽  
Construction Process ◽  
Engineering Structures ◽  
Replacement Method ◽  
Dynamic Replacement ◽  
Column Formation ◽  
Highway Embankment

Abstract This paper presents the analysis of the influence of works related to the dynamic replacement column formation on the bridge pillar and the highway embankment located nearby. Thanks to DR columns, it is possible to strengthen the soil under road embankment in a very efficient way. However, the construction of such support carries risk to buildings and engineering structures located in the neighbourhood. Therefore modelling and monitoring of the influence of the conducted works should be an indispensable element of each investment in which dynamic replacement method is applied. The presented issue is illustrated by the example of soil strengthening with DR columns constructed under road embankment of DTŚ highway located in Gliwice. During the inspection, the influence of vibrations on the nearby bridge pillar and road embankment was examined. The acceleration values obtained during these tests were used to verify the elaborated numerical model.

scholarly journals The influence of loading plate diameter on the results of trial load tests of dynamic replacement columns

2017 ◽  
Vol 2017 (5) ◽  
pp. 1-9
Author(s):  
Sławomir Kwiecień
Keyword(s):  
Numerical Model ◽  
Bearing Capacity ◽  
Deformation Modulus ◽  
Isotropic Hardening ◽  
Replacement Method ◽  
Dynamic Replacement ◽  
Load Tests

The dynamic replacement method of soil strengthening consists in the constructing columns made of aggregate of various granularity. In order to form them, heavy pounders (weighing from 10 to 20 tonnes) are dropped from the height of 25 m. Considering the specificity of this technique, it is quite important to verify on site the assumptions of the project, such as diameter and length of columns, their compaction or stiffness. For that reason, a number of examinations are performed, including column excavations, various types of probing tests or trial loads. The latter consists in determining the “load-settlement” dependence - usually during initial and secondary loadings phase – and on their basis, indicating the value of deformation modulus. Therefore, a stiff plate is placed on the column head and the loading is realised using actuators leaning on the ballast. The diameter of the loading plate depends on diameter and length of column and on the predicted pressure under the plate. The diameter of the loading plate is often smaller than column's diameter. This paper tries to determine the influence of the diameter of the plate used in test loads on the result of the research presented as “load-settlement” dependence and on the values of deformation modulus determined on their basis. The calculations were performed using FEM on a spatial numerical model calibrated on the basis of column's bearing capacity tests. Two models were applied in calculations: elastic-ideally plastic and isotropic hardening elastoplastic.

scholarly journals The Influence of Dynamic Replacement Method on the Adjacent Soil

2017 ◽  
Vol 16 (10) ◽  
pp. 1515-1522
Author(s):  
Jerzy Sękowski ◽  
Sławomir Kwiecień ◽  
Piotr Kanty
Keyword(s):  
Replacement Method ◽  
Dynamic Replacement ◽  
Adjacent Soil

Applied Research on Dynamic Replacement Method in Tailings Residue Subgrade Reinforcement

2013 ◽  
Vol 639-640 ◽  
pp. 943-946
Author(s):  
Jiao Long He ◽  
Yong Zhou ◽  
Zhong Ai Jiang
Keyword(s):  
Applied Research ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Field Testing ◽  
Standard Penetration Test ◽  
Load Test ◽  
Test Results ◽  
Replacement Method ◽  
Dynamic Replacement ◽  
Testing Experiment

Based on the reinforcing mechanism of dynamic replacement method ,this article put forward the construction parameters and measures of dynamic replacement method , combining with the result of actual engineering field testing experiment. The field load test, standard penetration test and pore water pressure test results show that the characteristic value of subgrade bearing capacity is more than 130 kpa when the tailings residue subgrade has been managed with dynamic replacement method, providing references for applied research on dynamic replacement method in tailings residue subgrade reinforcement.

Spallation of Concrete under Dynamic Loading: Mesh Size Effect

2011 ◽  
Vol 50-51 ◽  
pp. 929-933
Author(s):  
L. Yuan ◽  
Tao Xu ◽  
Q. Xu
Keyword(s):  
Numerical Model ◽  
Dynamic Loading ◽  
Stress Wave ◽  
Numerical Models ◽  
Failure Process ◽  
Mesh Size ◽  
Engineering Structures ◽  
One Dimensional ◽  
Failure Patterns ◽  
Concrete Materials

Spallation of concrete under dynamic loading has been the hot issue of concern about civil engineering structures and protective engineering. In the present paper, the principle of propagation of stress wave and the induced spallation process along a one-dimensional bar and the RFPA-Dynamics code which considers the heterogeneity of the concrete materials are briefly introduced. In order to numerically investigate the effect of mesh size of numerical model on the computational results, the failure process of concrete with three mesh sizes under dynamic loads was numerically simulated using RFPA-Dynamics code. Numerical simulations show that the failure patterns of concrete with different mesh sizes under dynamic stress waves are different. It is found that for the numerical models with the same mechanical parameters, the smaller mesh size of the numerical model is, the longer propagation of stress wave delay, the smaller the compressive stress is, thus the greater the tensile stress is, and the number of cracks is increasing, in general, rupture is more serious. The accuracy of mesh is little to improve when the number of the grid increases to a certain value.

scholarly journals Analysis of Changes of Forces and Normal Stress in Extradosed Tendons of the MS-3B Bridge Located on the Ring Road in Ostróda

2018 ◽  
Vol 196 ◽  
pp. 02050
Author(s):  
Tadeusz Stefanowski ◽  
Piotr Supeł ◽  
Wojciech Trochymiak
Keyword(s):  
Numerical Model ◽  
Normal Stress ◽  
Concrete Bridges ◽  
Normal Stresses ◽  
Construction Process ◽  
Next Generation ◽  
Global Trends ◽  
Ring Road ◽  
Live Loads ◽  
National Road

The article discusses the analyses of a numerical model of an extradosed bridge built as part of the project called “Construction of S7 expressway connecting Miłomłyn and Olsztynek, together with construction of Ostróda Bypass as a section of national road no. 16.” The constructed facility fits in with the global trends of construction of next generation concrete bridges with tensioned tendons. The bridge is the best in its class in Europe in terms of the length of its main span. It is also one of the first concrete bridges in Poland which have been built using cantilever technology in which the extradosed tendons were stressed during construction process. The article contains, in particular, the selected results of the analyses related to changes of forces and normal stresses in extradosed tendons depending on live loads to which the bridge was exposed during the service phases, while accounting for environmental and rheological as well as passage of time.

scholarly journals A 2-D numerical model of the mechanical behavior of the textile-reinforced concrete composite material: effect of textile reinforcement ratio

2020 ◽  
Vol 61 (3) ◽  
pp. 51-59 ◽  
Author(s):  
Tien Manh Tran ◽  
Tu Ngoc Do ◽  
Ha Thu Thi Dinh ◽  
Hong Xuan Vu ◽  
Emmanuel Ferrier ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Reinforced Concrete ◽  
Numerical Model ◽  
Mechanical Behavior ◽  
Basalt Fiber ◽  
Reinforcement Ratio ◽  
Experimental Results ◽  
Textile Reinforced Concrete ◽  
Engineering Structures

The textile-reinforced concrete composite material (TRC) consists of a mortar/concrete matrix and reinforced by multi-axial textiles (carbon fiber, glass fiber, basalt fiber, etc.). This material has been used widely and increasingly to reinforce and/or strengthen the structural elements of old civil engineering structures thanks to its advantages. This paper presents a numerical approach at the mesoscale for the mechanical behavior of TRC composite under tensile loading. A 2-D finite element model was constructed in ANSYS MECHANICAL software by using the codes. The experimental results on basalt TRC composite from the literature were used as input data in the numerical model. As numerical results, the basalt TRC provides a strain-hardening behavior with three phases, depending on the number of basalt textile layers. In comparison with the experimental results, it could be found an interesting agreement between both results. A parametric study shows the significant influence of the reinforcement ratio on the ultimate strength of the TRC composite. The successful finite element modeling of TRC specimens provides an economical and alternative solution to expensive experimental investigations.

scholarly journals A modeling algorithm for exploring the architecture and construction of bird nests

2019 ◽  
Author(s):  
Hadass R. Jessel ◽  
Lior Aharoni ◽  
Sol Efroni ◽  
Ido Bachelet
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Dead Sea ◽  
Nest Construction ◽  
Complex Structures ◽  
Construction Process ◽  
Biological Objects ◽  
Contact Points ◽  
Global Properties ◽  
And Behavior

AbstractNatural biological structures are often complex and cannot be mapped directly to genes, being therefore impossible to explore by traditional biological tools. In contrast, digitizing these structures enables to explore their properties and behavior under specific conditions, by means of computational manipulations, simulations, and analyses. We describe a generic algorithm for the digitization and exploration of the complex structures exhibited by common, interwoven bird nests. This algorithm takes as input computerized tomographic scans of the studied Dead-Sea Sparrow (Passer moabiticus) nest, identifies and isolates each branch entity within the three-dimensional data and finally extracts the characteristics of each branch. The result is a reliable three-dimensional numerical model of the nest that contains a complete geometric dataset per each of its components, e.g. dimensions and contact points with neighboring components, as well as global properties, e.g. density distribution and network structure. Based on these, we were able to simulate various models of the nest construction process. Altogether, the described algorithm and possible derivatives thereof could be a valuable tool in studying the structure-function relationships of similarly complex biological objects.

scholarly journals Research on the mechanism of the influence of flooding on the killing of empty wells

2021 ◽  
Vol 11 (9) ◽  
pp. 3571-3598
Author(s):  
Jie Zhang ◽  
Zaipeng Zhao ◽  
Xin Li ◽  
Yundong Zheng ◽  
Cuinan Li ◽  
...  
Keyword(s):  
Surface Tension ◽  
Droplet Diameter ◽  
Drill Pipe ◽  
Outer Diameter ◽  
Fluid Viscosity ◽  
Replacement Method ◽  
Dynamic Replacement ◽  
Calculation Results ◽  
Casing Pressure ◽  
Pipe Joint

AbstractIn empty well killing, in order to save the time and cost of killing the well, the dynamic replacement method is often used to kill the well. The main problem of the dynamic replacement method for killing wells is how to avoid terrible working conditions caused by flooding, such as gas carrying fluid, killing fluid being brought to the wellhead. Based on the principle of flooding formation and the basic tenets of flooding correlation experiment and dynamic replacement method, this paper incorporates the kill fluid viscosity, surface tension, droplet diameter, inclination angle, drill pipe joint outer diameter, and drill pipe eccentricity into the calculation range and establishes a new mathematical model suitable for dynamic replacement kill. Based on the calculation results, the influencing factors of flooding are analyzed, and the following conclusions are drawn: the increase of dynamic viscosity, gas density in the well, casing pressure, well angle, the outside diameter of drill pipe, the outer diameter of drill pipe joint, and eccentricity of drill pipe can promote the occurrence of flooding; The increase of surface tension, well-killing fluid density, and casing inner diameter have an obstacle to flooding.

Large Scale Physical Modelling for a Floating Concrete Caisson in Marine Works

2018 ◽  
Author(s):  
Lucía Meneses ◽  
Javier Sarmiento ◽  
Daniel de los Dolores ◽  
David Blanco ◽  
Raúl Guanche ◽  
...  
Keyword(s):  
Life Cycle ◽  
Numerical Model ◽  
Large Scale ◽  
Physical Modelling ◽  
Dynamic Positioning ◽  
Construction Process ◽  
Important Advance ◽  
Positioning Control ◽  
Floating Structures ◽  
Vertical Breakwater

In the last years, the use of floating concrete caissons in coastal infrastructures has been generalized: docking structures, vertical breakwater and special floating structures. In this field, one of the most important and less analyzed stages of the marine works is the sinking process of the floating caissons. The test campaign presented in this work is innovative in scale (1:12) and includes an analysis of the different stages of a floating caisson during its life cycle: detached concrete caisson, caisson positioning and sinking and berthed floating caisson, resulting in more than 130 tests performed. Movements and tensions have been analyzed for a wide array of sea states and different configurations of mooring systems and horizontal layouts. A new tool for dynamic positioning control was designed and developed as part of the test campaign. The design of this tool has led to the development of a specific numerical model that reproduced the dynamic behavior during sinking. The dynamic positioning control was implemented in the physical model campaign, which has meant an important advance in the construction process of maritime infrastructures. Moreover, the campaign carried out has allowed the validation and calibration of the tools developed, allowing all the work to reduce costs and increase the safety of these types of marine operations.

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