A simple procedure for computation of vertical soil stresses for surface regions of arbitrary shape and loading

1987 ◽  
Vol 24 (1) ◽  
pp. 143-145 ◽  
Author(s):  
J. C. Thompson ◽  
B. Lelievre ◽  
R. D. Beckie ◽  
K. J. Negus
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Arbitrary Shape ◽  
Simple Procedure ◽  
Surface Region ◽  
Vertical Stress ◽  
Computer Algorithms ◽  
Computer Solution ◽  
Analysis Technique ◽  
Mathematical Operations

Based on the Boussinesq formula, exact formulae are derived for the vertical stress beneath the corner of an arbitrarily shaped triangular surface region subjected to vertical pressures with a uniform, linear, or quadratic distribution. These formulae are the basis of a proposed analysis technique in which any arbitrarily shaped loading region is approximated by a set of triangular regions. Computer algorithms that take advantage of the highly repetitive, yet simple, mathematical operations can readily be implemented on the computational facilities currently available to most engineers. Key words: triangular or arbitrarily shaped load regions, vertical stress distribution, computer solution.

Selection of operative centrifuge radius to minimize stress error in calculations

1991 ◽  
Vol 28 (1) ◽  
pp. 160-161 ◽  
Author(s):  
Brian Cooke
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Gravity Field ◽  
Vertical Stress ◽  
Centrifugal Acceleration ◽  
Centrifuge Model ◽  
Definition Of ◽  
Centre Of Rotation ◽  
Selection Of ◽  
Stress Error

In a centrifuge model, the vertical stress distribution is nonlinear because of the variation of the model's "gravity" field with the centrifuge radius from the top to the bottom of the model. Thus in calculating the centrifugal acceleration, and hence the scale of the model, care must be taken to use the definition of centrifuge radius that minimizes the stress error in the model profile. This paper demonstrates that this optimum radius is measured from the centre of rotation to a point 0.59 times the model height from the bottom of the model. Key words: centrifuge, stress, error.

A chart for estimating the average vertical stress increase in an elastic foundation below a uniformly loaded rectangular area

1984 ◽  
Vol 21 (4) ◽  
pp. 710-713 ◽  
Author(s):  
D. V. Griffiths
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Vertical Stress ◽  
Limited Data ◽  
Stress Increment ◽  
Surface Loading ◽  
Stress Increase ◽  
Measured Stress ◽  
Stress Components ◽  
Rectangular Area

In spite of the considerable assumptions involved, stress distribution charts based on elastic theory are still used by engineers to estimate stresses induced in soil masses by surface loading. Although there are limited data comparing calculated and measured stress increments, vertical stress components have been predicted quite reliably by this method. The chart presented here enables the average vertical stress increment beneath a corner of a uniformly loaded rectangular area to be estimated. The results are based on numerical integration of existing solutions for the rectangle problem, and should reduce the need for sublayers when calculating consolidation settlements. Key words: stress distribution, elasticity, design graph, rectangular footing, consolidation.

scholarly journals Stress and deformation analysis of gob-side pre-backfill driving procedure of longwall mining: a case study

2021 ◽  
Author(s):  
Rui Wu ◽  
Penghui Zhang ◽  
Pinnaduwa H. S. W. Kulatilake ◽  
Hao Luo ◽  
Qingyuan He
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Coal Seam ◽  
Abutment Pressure ◽  
Longwall Mining ◽  
Vertical Stress ◽  
Floor Level ◽  
Working Face ◽  
Floor Heave ◽  
Stress And Deformation

AbstractAt present, non-pillar entry protection in longwall mining is mainly achieved through either the gob-side entry retaining (GER) procedure or the gob-side entry driving (GED) procedure. The GER procedure leads to difficulties in maintaining the roadway in mining both the previous and current panels. A narrow coal pillar about 5–7 m must be left in the GED procedure; therefore, it causes permanent loss of some coal. The gob-side pre-backfill driving (GPD) procedure effectively removes the wasting of coal resources that exists in the GED procedure and finds an alternative way to handle the roadway maintenance problem that exists in the GER procedure. The FLAC3D software was used to numerically investigate the stress and deformation distributions and failure of the rock mass surrounding the previous and current panel roadways during each stage of the GPD procedure which requires "twice excavation and mining". The results show that the stress distribution is slightly asymmetric around the previous panel roadway after the “primary excavation”. The stronger and stiffer backfill compared to the coal turned out to be the main bearing body of the previous panel roadway during the "primary mining". The highest vertical stresses of 32.6 and 23.1 MPa, compared to the in-situ stress of 10.5 MPa, appeared in the backfill wall and coal seam, respectively. After the "primary mining", the peak vertical stress under the coal seam at the floor level was slightly higher (18.1 MPa) than that under the backfill (17.8 MPa). After the "secondary excavation", the peak vertical stress under the coal seam at the floor level was slightly lower (18.7 MPa) than that under the backfill (19.8 MPa); the maximum floor heave and maximum roof sag of the current panel roadway were 252.9 and 322.1 mm, respectively. During the "secondary mining", the stress distribution in the rock mass surrounding the current panel roadway was mainly affected by the superposition of the front abutment pressure from the current panel and the side abutment pressure from the previous panel. The floor heave of the current panel roadway reached a maximum of 321.8 mm at 5 m ahead of the working face; the roof sag increased to 828.4 mm at the working face. The peak abutment pressure appeared alternately in the backfill and the coal seam during the whole procedure of "twice excavation and mining" of the GPD procedure. The backfill provided strong bearing capacity during all stages of the GPD procedure and exhibited reliable support for the roadway. The results provide scientific insight for engineering practice of the GPD procedure.

Reinforced Circular Holes in Bending With Shear

1953 ◽  
Vol 20 (2) ◽  
pp. 279-285
Author(s):  
S. R. Heller
Keyword(s):  
Stress Distribution ◽  
Arbitrary Shape ◽  
Theoretical Solution ◽  
Bead Type ◽  
Circular Holes ◽  
Radial Thickness ◽  
Bending With Shear ◽  
The Web

Abstract The object of this paper is the determination of the effect of the reinforcement of circular holes on the stress distribution in the webs of beams subjected to bending with shear. A theoretical solution for a bead-type reinforcement, i.e., small radial thickness, is developed. The stress distribution in the web for arbitrary shape reinforcement is based on the work of Reissner and Morduchow (1). The theory developed is valid provided the diameter of the hole does not exceed one fourth of the depth of the beam.

scholarly journals ANALISA PUBLIC FINANCE MANAGEMENT KABUPATEN MERAUKE

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Ida Ayu Purba Riani
Keyword(s):  
Public Finance ◽  
Key Words ◽  
Local Governments ◽  
Primary Data ◽  
Cash Management ◽  
Regional Autonomy ◽  
Finance Management ◽  
Analysis Technique ◽  
The Ideal

In the era of regional autonomy, managements in local governments set out accountability and transparency in managing the regional public finance including planning, budgeting, implementation, administering, reporting, accountable and controlling. As from writer’s observation of development performance in Merauke regency, it revealed that there was inadequate development in reaching the ideal development performance although the management was generally well-managed. This paper applied Public Finance Management analysis technique to analyse primary data. The results showed the overall score was 52% from total statements which including 9 sectors. The highest scores were in the planning, cash management, procurement as well as accounting and reporting areas. Key words: Public Finance, Management, Accountability.

scholarly journals Upaya Meningkatkan Kreativitas Anak melalui Permainan Finger Painting Usia 5-6 Tahun di TK Harapan Bunda Pekanbaru

2018 ◽  
Vol 2 (01) ◽  
pp. 31-39
Author(s):  
Jumilah Jumilah ◽  
Sean Marta Efastri ◽  
Siti Fadillah
Keyword(s):  
Initial Data ◽  
Key Words ◽  
Average Increase ◽  
Research Results ◽  
Class Actions ◽  
Analysis Technique ◽  
Determination Methods ◽  
Definition Of ◽  
Children's Development ◽  
Children’S Development

Abstrak Kreativitas adalah kemampuan untuk menciptakan sesuatu yang baru yang berupa gagasan maupun karya nyata. Adapun tujuan dari penelitian yaitu untuk mendapatkan data perkembangan kreativitas anak  melalui permainan finger painting. Metode penelitian yang digunakan adalah Penelitian Tindakan Kelas ( PTK) . Subjek yang diambil untuk penelitian  terdiri dari 15 anak di TK Harapan Bunda. Teknik pengumpulan data dalam penelitian ini adalah melalui lembar observasi, dan dokumentasi. Teknik analisis data yaitu dengan menggunakan rumus persentase= f/n x100 % . Hasil penelitian data yang diperoleh  dalam meningkatkan perkembangan kreativitas anak melalui permainan finger painting, sebelum tindakan adalah 59 %  ( Mulai Berkembang / MB ) dan meningkat pada siklus I dengan kategori BSH “ Berkembang Sesuai Harapan”  dengan rata – rata peningkatan 71 % dan pada siklus II mengalami peningkatan dengan kategori BSB “ Berkembang Sangat Baik” yaitu rata-rata 84 %. Jadi peningkatan kreativitas anak dari data awal 59 %  ke data siklus II 84 %, terjadi peningkatan sebanyak 25 %.    Kata  Kunci :  Kreativitas Anak,   permainan  finger painting Abstract Creativity is the ability to create a new something which is in the form of ideas or real works. There is a purpose of definition that is to get data of children's development creativity through Finger painting games. Determination methods used are definition of class actions (ptk). Observation sheet, and documentation. Analysis technique is using the percentage formula f / n x 100%. The research results obtained in improving the development of children's creativity through finger painting, before the action was 59% (developing / mb) and increasing in the first cycle with the bsh category "developing as expected" with an average increase of 71% and in the second cycle experiencing an increase with the bsb category "develops very well" which is an average of 84%. So increasing children's creativity from the initial data of 59% to data cycle ii 84%, an increase of 25%. Key words : children's creativity, finger painting game

Steady-State stress distributions in circumferentially notched bars subjected to creep

1982 ◽  
Vol 17 (3) ◽  
pp. 123-132 ◽  
Author(s):  
K D Al-Faddagh ◽  
R T Fenner ◽  
G A Webster
Keyword(s):  
Steady State ◽  
Stress Distribution ◽  
Stress Index ◽  
Stress Distributions ◽  
Computer Solution ◽  
Time Intervals ◽  
Throat Region ◽  
Intermediate Time ◽  
State Stress ◽  
Good Agreement

The paper describes a procedure, based on a finite element method, for calculating directly the steady-state stress distribution in circumferentially notched bars subjected to creep without the need for obtaining solutions at intermediate time intervals. Good agreement is obtained with relevant approximate plasticity solutions and with numerical calculations which approach the steady-state over a period of time from the initial elastic stress distribution. Also, the procedure is equally applicable to primary, secondary, and tertiary creep, provided the variables of stress and time are separable in the creep law. Results obtained for a range of notch geometries and values of the stress index, n, are reported. It is found for each profile that a region of approximately constant effective stress, σ, independent of n, is obtained which can be used to characterise the overall behaviour of the notch throat region when a steady-state is reached sufficiently early in life. An approximate method for estimating the maximum equivalent steady-state stress across the notch throat is also presented which does not require a computer solution.

Vertical Stress Distributions of a Thin Rectangular Steel Wall Under Compression and in-Plane Bending

2020 ◽  
Vol 20 (08) ◽  
pp. 2050090
Author(s):  
Yang Lv ◽  
Jia-Qi Lv ◽  
Zheng Zhao
Keyword(s):  
Shear Strength ◽  
Stress Distribution ◽  
Shear Wall ◽  
Vertical Stress ◽  
Thin Wall ◽  
Effective Width ◽  
Steel Shear Wall ◽  
Gravity Load ◽  
Plane Bending ◽  
Minimum Stress

A thin rectangular steel wall in a steel shear wall structure always simultaneously sustains the lateral load and the gravity load. The gravity load can affect the shear strength of a steel shear wall. However, this effect is not considered in most of the research and standards, which may lead to potential danger in practice. From the previous study of the authors, the shear strength reduction was not only influenced by the load magnitude but also by the vertical stress distribution. For a simply-supported thick square wall, i.e. width to thickness ratio smaller than 100, the stress distribution can be accurately described in a cosine form. However, for a thin wall under compression and in-plane bending, the cosine distribution will largely overestimate the vertical stress, especially when the walls enter the post-buckling condition. To narrow the knowledge gap, this paper proposed a vertical stress distribution in a three-segment form, i.e. in both edge-segments, a combination of linear and cosine functions from the edge stresses to the minimum stress, while in the middle segment, the stress distribution is constant and equal to the minimum stress. Two strategies, i.e. effective width method and Bedair’s method, are chosen to determine the width of the edge portion. A finite element model (FEM) is developed to evaluate the proposed distribution. The FEM has been verified using the results of our own experiments and tests done by Zaraś et al. The results show that the proposed three-segment stress distribution can well describe the behavior of thin walls of different slendernesses and stress gradients. The cosine distribution obtained from theoretical solution and the effective width model by Bedair are also discussed.

The Interface Boundary Conditions for Bolted Flanged Connections

1976 ◽  
Vol 98 (4) ◽  
pp. 277-282 ◽  
Author(s):  
J. C. Thompson ◽  
Y. Sze ◽  
D. G. Strevel ◽  
J. C. Jofriet
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Plate Theory ◽  
Contact Region ◽  
Three Dimensional ◽  
Surface Region ◽  
Prestressing Force ◽  
Flange Thickness ◽  
Interface Boundary Conditions ◽  
Contact Stress Distribution

In most bolted connections, the unknown interface pressure distribution and the extent of the contact region are essential parameters in any stress analysis. Concerning these parameters, experimental and numerical studies of a model of an isolated single-bolt region show the following. The contact region between the flanges depends almost exclusively on the ratio of the flange thickness to the diameter of the surface region of each flange over which the bolt prestressing force is distributed; the contact zone is virtually independent of both the level of prestressing force and of the size of the bolt hole; and the contact stress distribution for a typical range of parameters is very closely approximated by a truncated conical distribution. The studies also delineate the regions of the flanges around each bolt where the stress state is strongly three-dimensional and regions where simple plate theory is applicable. The relationships established between the contact stress distribution and the various geometric parameters are presented in a form immediately applicable by designers.

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