The Influence of Dynamic Replacement Method on the Adjacent Soil

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.

Download Full-text

Analysis Of Dynamic Replacement Column Construction Process On Neighbouring Engineering Structures

Archives of Civil Engineering ◽

10.1515/ace-2015-0021 ◽

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.

Download Full-text

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

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01265-4 ◽

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.

Download Full-text

Influence of Load Plates Diameters, Shapes of Columns and Columns Spacing on Results of Load Plate Tests of Columns Formed by Dynamic Replacement

Sensors ◽

10.3390/s21144868 ◽

2021 ◽

Vol 21 (14) ◽

pp. 4868

Author(s):

Sławomir Kwiecień

Keyword(s):

Numerical Models ◽

Constitutive Models ◽

Isotropic Hardening ◽

Load Testing ◽

Perfectly Plastic ◽

Replacement Method ◽

Dynamic Replacement ◽

Modified Cam Clay ◽

Load Tests ◽

Elastic Perfectly Plastic

The dynamic replacement method is used to strengthen the subgrade of objects, usually up to 5 to 6 m thick. After the improvement process, acceptance tests in the form of load testing are carried out. Interpretation of the test results can cause some difficulties. Dynamic replacement results in a situation where columns of different shapes, loaded with plates of diameters usually smaller than the head diameter and in the vicinity of adjacent columns, are subjected to load tests. In order to demonstrate the influence of these factors, a spatial model of soil strengthened by dynamic replacement, comprising four material zones, was calibrated on the basis of load testing. The following models were used in the analysis: linear-elastic, elastic–perfectly plastic (Coulomb–Mohr) and elastic–plastic with isotropic hardening (Modified Cam-Clay). This formed the basis for 105 numerical models, which took into account the actual shapes of the columns made at various spacings, subjected to load tests with plates of various diameters. The analyses of the settlements, calculated moduli and stress distribution in the loaded system showed how the results were significantly influenced by mentioned factors. This implies that the interpretation of the results of load tests should be based on advanced spatial numerical analyses, using appropriate constitutive models and including the considered factors.

Download Full-text

Numerical Simulation of Crater Creating Process in Dynamic Replacement Method by Smooth Particle Hydrodynamics

Studia Geotechnica et Mechanica ◽

10.2478/sgem-2014-0022 ◽

2015 ◽

Vol 36 (3) ◽

pp. 3-8 ◽

Cited By ~ 6

Author(s):

Andrzej Danilewicz ◽

Zbigniew Sikora

Keyword(s):

Time Integration ◽

Smoothing Function ◽

Smooth Particle Hydrodynamics ◽

Sph Method ◽

Replacement Method ◽

Dynamic Replacement ◽

Boundary Treatment ◽

Particle Hydrodynamics ◽

Integration Techniques ◽

Method Accuracy

Abstract A theoretical base of SPH method, including the governing equations, discussion of importance of the smoothing function length, contact formulation, boundary treatment and finally utilization in hydrocode simulations are presented. An application of SPH to a real case of large penetrations (crater creating) into the soil caused by falling mass in Dynamic Replacement Method is discussed. An influence of particles spacing on method accuracy is presented. An example calculated by LS-DYNA software is discussed. Chronological development of Smooth Particle Hydrodynamics is presented. Theoretical basics of SPH method stability and consistency in SPH formulation, artificial viscosity and boundary treatment are discussed. Time integration techniques with stability conditions, SPH+FEM coupling, constitutive equation and equation of state (EOS) are presented as well.

Download Full-text

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

Transportation Overview - Przeglad Komunikacyjny ◽

10.35117/a_eng_17_05_01 ◽

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.

Download Full-text