scholarly journals THE FORECAST OF LONG-TERM SETTLEMENT OF THE PILE ON SANDSTONES AND CLAYSTONES OF THE PERMIAN AGE

2019 ◽  
Vol 10 (2) ◽  
pp. 5-13
Author(s):  
E. N Sychkina ◽  
I. V Ofrikhter ◽  
V. V Antipovov

In the article the problem of ensuring the long-term settlement of single piles on claystones and sandstones are reviewed. Incorrect assessment of stabilized settlement of pile foundation can lead to an emergency situation. At the present time for prediction of foundation settlement is widely used finite element method, implemented in a variety of software systems. The aim of the study was to select the optimal model in the software package Plaxis 3D to forecast settlement of driven and bored piles on claystones and sandstones. The authors solved the following tasks: 1) review of the knowledge of long-term settlement of single piles and pile foundations on claystonese and sandstones is performed; 2) the technique is described and numerical experiments are performed in the software package Plaxis 3D for modeling the settlement of a single driven pile and bored pile on claystones and sandstones with varying degrees of weathering; 3) comparison of the results of numerical experiments with long-term field tests of piles on claystones and sandstones is performed; 4) findings from the study are formulated. Numerical experiments of modeling in the software package Plaxis 3D work of driven piles on claystones and sandstones showed that the introduction of soil compaction zones around the driven pile into the calculation scheme makes it possible to obtain close values to long-term settlement of full-scale piles. The authors recommend using the Hardening soil model to predict the work of a driven pile on claystones and sandstones and the Linear-Elastic model to simulate the work of a bored pile on claystones and sandstones. For highly weathered claystones and sandstones soil models need to be corrected for numerical calculations in Plaxis 3D, since the use of the Hardening soil and Linear-Elastic models showed underestimated settlement values in relation to field tests of driven piles.

2011 ◽  
Vol 105-107 ◽  
pp. 1415-1419 ◽  
Author(s):  
Shih Tsung Hsu

This study developed a numerical method to establish a comprehensive load-settlement curve for a driven pile. Analysis results shown that the residual forces caused by the driving of the pile can be simulated using the numerical method that proposed herein. The load was applied to the tested piles, while the incremental displacement was subjected to numerical piles. Although these two processes are distinctive, the load-settlement behaviors of various piles calculated numerically are consistent with those measured from field tests. Moreover, the proposed numerical method highlighted the post-peak behavior of a pile. Accordingly, the numerical method was very suitable to analyze the behavior of driven piles.


Vestnik MGSU ◽  
2019 ◽  
pp. 188-198
Author(s):  
Evgeniya N. Sychkina ◽  
Vadim V. Antipov ◽  
Yan V. Ofrikhter

Introduction. Reviewed the features of the work of the pile on Permian claystones with the help of numerical and field experiments, analytical calculations. Materials and methods. Numerical modeling was performed in the Plaxis 3D and Midas GTS NX software packages. Full-scale tests of driven piles are made in accordance with the requirements of GOST 20276-2012. The obtained results are compared with the results of analytical calculations according to SP 24.13330.2011. Results. The scientific novelty of the investigation consists in a comparative analysis of the results of numerical modeling of the interaction of a driving pile with claystones with the results of field tests and analytical calculations. Finite element analysis in software package Plaxis 3D using Hardening Soil model shows higher values of settlement (up to 6 times) in relation to stabilized settlement of full-scale pile tests. Calculations in the software package Midas GTS NX showed overestimated values of pile settlements in relation to full-scale pile tests (13-24 times). Analytical calculations in accordance with SP 24.13330.2011 also showed overestimated (up to 3 times) values of the maximum pile settlement in relation to the stabilized settlement during full-scale pile tests. Conclusions. The calculations by the finite element method in the package Plaxis 3D and Midas GTS NX, by the analytical method according to SP 24.13330.2011, show overestimated values of settlement in relation to the stabilized settlement of piles on claystones. Using the Linear-Elastic model for claystones in numerical calculations in Plaxis 3D provides a value close to the settlement of full-scale pile. However, the use of this model is not fully justified for claystones due to the presence of residual deformations and the nonlinear character of pile settlement during loading. Necessary to correct the existing numerical and analytical methods for calculating pile foundations on claystones. It is necessary to continue the work on the further generalization of the experience of arranging piles on weathered claystones in order to evaluate the long-term work of not only a single pile, but also a pile foundation.


Author(s):  
Jairo Bastos de Araujo ◽  
Roge´rio Diniz Machado ◽  
Cipriano Jose de Medeiros Junior

Petrobras developed a new kind of anchoring device known as Torpedo. This is a steel pile of appropriate weight and shape that is launched in a free fall procedure to be used as fixed anchoring point by any type of floating unit. There are two Torpedoes, T-43 and T-98 weighing 43 and 98 metric tons respectively. On October 2002 T-43 was tested offshore Brazil in Campos Basin. The successful results approved and certified by Bureau Veritas, and the need for a feasible anchoring system for new Petrobras Units in deep water fields of Campos Basin led to the development of a Torpedo with High Holding Power. Petrobras FPSO P-50, a VLCC that is being converted with a spread-mooring configuration will be installed in Albacora Leste field in the second semester of 2004. Its mooring analysis showed that the required holding power for the mooring system would be very high. Drag embedment anchors option would require four big Anchor Handling Vessels for anchor tensioning operations at 1400 m water depth. For this purpose T-98 was designed and its field tests were completed in April 2003. This paper discusses T-98 design, building, tests and ABS certification for FPSO P-50.


Author(s):  
Vladimir Ivanovich Matselya ◽  
Igor Nikolaevich Seelev ◽  
Alexey Valentinovich Lekontsev ◽  
Robert Rafaelevich Khafizov ◽  
Pavel Viktorovich Yakovlev ◽  
...  

The popularity of numerical methods for modeling soil bases determines the increased demand for the accuracy of calculations. The choice of a model that meets the requirements of accuracy of calculations and minimization of costs is determined by comparative analysis of common soil models described in scientific literature and used in calculations of sediments and dynamic effects of buildings (finite element linear elastic, elastic, ideal-plastic, Mora - Coulomb with strengthening, elasto-plastic with strengthening at small deformation). The results have been obtained on test models using finite element method in the environment of PLAXIS 3D and SCAD Office programs. In order to compare results obtained, subject to requirements of the current regulatory documents, a comparative analysis of soils was carried out according to the model of Body of rules 22.13330.2011 "Foundations of buildings and structures". The analysis results were used for choosing an optimal model of soil bases of industrial buildings estimated in earthquake-proof design. It should be noted that the strong and weak points identified for each model justify the choice of the best model for each particular case.


2017 ◽  
Vol 24 (3) ◽  
pp. 106-114 ◽  
Author(s):  
Mikołaj Miśkiewicz ◽  
Oskar Mitrosz ◽  
Tadeusz Brzozowski

Abstract Appropriate risk assessment plays a fundamental role in the design. . The authors propose a possible method of design risk mitigation, which follows recommendations included in Eurocode 7. The so-called “Observational Method” (OM) can produce savings in costs and programmes on engineering projects without compromising safety. The case study presented is a complex design solution that deals with the heavy foundations of a gantry crane beam as one of the elements of a Deepwater Container Terminal extension. The paper presents a detailed process of the design of the rear crane beam being a part of the brand new berth, together with its static analysis, as well as the long-term results of observations, which have revealed the real performance of the marine structure. The case presented is based on excessive preliminary field tests and technical monitoring of the structure, and is an example of a successful OM implementation and design risk mitigation.


1985 ◽  
Vol 12 (2) ◽  
pp. 382-395 ◽  
Author(s):  
Shamim A. Sheikh ◽  
Michael W. O'Neill ◽  
M. A. Mehrazarin

A hypothesis is presented in this paper that states that expansive cement concrete produces a stronger bond between the concrete in a drilled shaft (bored pile) and the surrounding soil than does normal cement; this results in an increase in the frictional component of capacity and a reduction in the settlement of the shaft at working load levels.Four types of expansive cement, type "K" cement (the expansive cement available commercially) and three made from commercially available materials, were tested for their expansion characteristics; two of them were selected to be used in two instrumented drilled shafts in stiff clay. Normal (type 1) cement was used in a third shaft to serve as a reference. The three shafts were tested to failure after essentially all the expansion was deemed to have taken place in the two expansive concrete shafts. Lateral and longitudinal expansion of the shafts were monitored during the curing period. Load–settlement behaviour and load transfer between shafts and soil during the tests were studied.The test results permitted the preliminary conclusion that expansive cement concrete can increase the frictional capacity of drilled shafts in stiff clay by as much as 50% and reduce the settlement by about 50%. The results are valid for short-term behaviour of drilled shafts made of expansive cement. The long-term behaviour of such shafts remains to be studied. Key words: base bearing capacity, bored pile, cement (expansive), concrete (structural), drilled shaft, ettringite, expansion, frictional capacity, settlement, stress path.


1992 ◽  
Vol 75 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Bertrand S Lanher

Abstract A new software package, ANAQUANT, was specifically designed for a long-term approach to the quantitation of compounds In biological products. Its functionality and validity were tested by measuring fat and protein contents In liquid cow's milk using Fourier transform Infrared spectrometry and a handcrafted transmission flow cell. Calibration and validation standard deviations were 0.2484 and 0.3987 g/kg, respectively, for the prediction of proteins, and 0.3163 and 0.4222 g/L, respectively, for the prediction of butterfat. One month elapsed between calibration of the Instrument and the validation study. Results are consistent with those proposed in the literature.


2015 ◽  
Vol 1124 ◽  
pp. 209-218
Author(s):  
Pavel Svoboda ◽  
Karl Heinz Winter

Reinforced and pre-stressed concrete have been used increasingly for various kinds of complex structures in the past decades. The structures assembled from panels belong into this group. The current design methods rely on linear elastic analyses based on empirically derived material laws assuming homogeneous and isotropic material. Practical experience and various investigations however have indicated that majority of structures and structural elements are in fact stressed beyond the range of linear elastic behavior. In addition, long term effects may have a significant influence on the structural behavior of this category of structures and structural members.


2007 ◽  
Vol 24 (4) ◽  
pp. 296-300 ◽  
Author(s):  
Yuhui Weng ◽  
Kathy Tosh ◽  
Yill Sung Park ◽  
Michele S. Fullarton

Abstract Polycross-pollinated white spruce (Picea glauca [Moench] Voss) families were evaluated in field and retrospective nursery tests in 1989, 1991, and 1992, respectively. Height growth was measured at age 10 for the field tests and at ages 1 to 6 for the retrospective nursery tests. Except for a few cases, the family mean correlations between nursery and field heights were significant for the 1989 and 1992 series, and their corresponding genetic correlations ranged from low to medium (from 0.37 to 0.74). Because of heavy noncrop competition, height growth in the 1991 nursery series showed consistently lower heritabilities and correlations with field performance compared with those of the other two series. Early nursery selection by theoretical prediction was generally efficient for the 1989 and 1992 series. Rank classification analysis indicated that application of early nursery selection should be used with caution for identifying elite families but could be used to cull inferior families or clones, apply multiple-stage selection, or perform positive assortative mating.


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