Calculation of Static Safety Coefficient about Loess Cave

For the loess cave characteristics, such as the thin coverage soil layer at the hole top, the poor self-stabilizing capacity, the large disturbance deformation after excavation and the easy collapse, thus in this paper, the loess cave safety factor is obtained by the method of strength reduction. And the stability calculation analysis is much more perfect. The Northwest Area Lishi loess cave is used in this paper, and the idea of strength reduction finite element method is applied, based on the Drucker-Prager yield criterion, the loess cave static stability analysis is made by the software of ANSYS.The results show that the actual situation can be reflected by the method of finite element strength subtraction. And the obtained loess cave stability coefficient is much closer to the actual steady state, thus showing the certain advantages of stability analysis.The method is also adopted in this paper. And its feasibility can be applied to the engineering practice, also a theoretical basis of reference is provided for engineering application.

ON STATIC STABILITY OF NONLINEARLY ELASTIC EULER'S COLUMNS OBEYING THE MODIFIED LUDWICK'S LAW

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455412500770 ◽

2012 ◽

Vol 12 (06) ◽

pp. 1250077 ◽

Cited By ~ 4

Author(s):

MIHA BROJAN ◽

MATEJ SITAR ◽

FRANC KOSEL

Keyword(s):

Constitutive Model ◽

Static Stability ◽

Engineering Practice ◽

Structural Systems ◽

Structural Elements ◽

Material Parameters ◽

Bifurcation Buckling ◽

Elastic Column ◽

The Stability ◽

Nonlinearly Elastic

It is illustrated in this paper that a nonlinearly elastic column, depending upon the values of different material parameters involved, exhibits several stability characteristics and types of buckling which are generally observed separately in distinctively different structural systems. By introducing finite disturbances it is shown that the column may buckle well before the bifurcation buckling load is reached. The proposed approach can be useful in engineering practice since it can be utilized to study the stability of uniaxial structural elements made from rubber or any other material which obeys the modified Ludwick's constitutive model.

The Analyses on Mechanism and Mode of Instability of Loess Slopes under Surface Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.3067 ◽

2011 ◽

Vol 243-249 ◽

pp. 3067-3071

Author(s):

Rong Jin Li ◽

Rong Jian Li ◽

Wen Zheng ◽

Juan Fang

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Loess Soil ◽

Strength Reduction ◽

Surface Load ◽

Soil Slope ◽

Surface Loading ◽

Loess Area ◽

Loess Slope ◽

The contribution of surface load to the stability of loess slope should be properly evaluated in order to meet the engineering demand in loess area. It is essential to analyze the stability of loess soil slope by means of the strength reduction finite element method instead of the slices method commonly used in practice so far. Firstly, some researches on stability of loess slope are reviewed. Then some different cases of the mechanism and mode of instability of a loess slope due to surface load are analyzed in this paper. Numerical results not only indicate that the safety factor of loess slope tends to change with the different distribution of the surface load, but also reveal that the distribution of surface load has important effect on the mode of instability of slope.

Stability Analysis of a 3D Vertical Slope with Transverse Earthquake Load and Surcharge

10.4028/www.scientific.net/amm.90-93.676 ◽

2011 ◽

Vol 90-93 ◽

pp. 676-679 ◽

Cited By ~ 2

Author(s):

Ting Kai Nian ◽

Ke Li Zhang ◽

Run Qiu Huang ◽

Guang Qi Chen

Keyword(s):

Finite Element ◽

Stability Analysis ◽

Failure Mode ◽

Factor Of Safety ◽

Three Dimensional ◽

Strength Reduction ◽

Reduction Procedure ◽

Interesting Issue ◽

Earthquake Load ◽

The stability and failure mode for a 3D vertical slope with transverse earthquake load and surcharge have been an interesting issue, especially in building excavation and wharf engineering. In order to further reveal the seismic and surcharge effect, a three-dimensional elasto-plastic finite element(FE) code combined with a strength reduction procedure is used to yield a factor of safety and failure mode for a vertical slopes under two horizontal direction pseudo-static(PS) coefficient and surcharge on the slope top, respectively. Comparative studies are carried out to investigate the effect of seismic coefficient, surcharge intensity and location on the stability and the failure mechanism for a 3D vertical slope including an inclined weak layer. Several important findings are also achieved.

The Research on Application of Strength Reduction Finite Element Method in Stability Analysis of Weak Intercalated Rock Tunnel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.1926 ◽

2011 ◽

Vol 255-260 ◽

pp. 1926-1929

Author(s):

Da Kun Shi ◽

Yang Song Zhang

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Rock Mass ◽

Safety Factor ◽

Slip Surface ◽

Strength Reduction ◽

Surrounding Rock ◽

Stability Of Surrounding Rock ◽

The Stability ◽

Element Method

Based on geologic condition of one tunnel surrounding rock mass, systematic numerical tests had been carried out to study the stability of surrounding rock mass with different distributions of weak intercalated rock by the FEM software ABAQUS and strength reduction finite element method. Some quantificational results about the stability of surrounding rock mass were summarized. And the safety factor and latent slip surface were worked out. The stability of surrounding rock mass was judged by strength reduction finite element method. According to the analysis above, it’s known that the discrepancy of two rules is small; the safety factor is the lowest when weak intercalated rock in vault, and when at bottom, it’s higher than that of in vault. The conclusion can be used to guide the procedure of construction and ensure the safety.

Stability Analysis of High Filling Slope Affected by Precipitation Intensity

10.4028/www.scientific.net/amm.170-173.1174 ◽

2012 ◽

Vol 170-173 ◽

pp. 1174-1178 ◽

Cited By ~ 1

Author(s):

Wen Tao Wang ◽

Tao Song ◽

Zeng Rong Liu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Slope Stability ◽

Precipitation Intensity ◽

Safety Coefficient ◽

Stability Of Slope ◽

Seepage Theory ◽

The Stability ◽

Unsaturated Seepage ◽

Element Method

Aiming at researching on stability of slope affected by precipitation intensity, transient saturated-unsaturated seepage finite element method and slope stability finite element method are combined in this paper. Vadose field of slope is simulated in different precipitation intensity. Based on vadose field, the writers analyzed the stability of slope affected by precipitation intensity. The research results indicate that water is brought together in the interface first. Then the water level moves toward up and down respectively from the both sides of the interface. On the basis of saturated-unsaturated seepage theory, precipitation intensity has little effect on the slope stability in the first 6 hours after precipitation. After that, slope safety coefficient is relatively high when precipitation intensity is smaller, and vice versa.

Research on Soil-Like Slope Instability Based on FEM Strength Reduction

10.4028/www.scientific.net/amm.438-439.1244 ◽

2013 ◽

Vol 438-439 ◽

pp. 1244-1248 ◽

Cited By ~ 1

Author(s):

Chun Ming Wang ◽

Chun Yuan Liu ◽

Mai Wu ◽

Xin Zhao

Keyword(s):

Finite Element ◽

Main Idea ◽

Strength Reduction ◽

Slope Instability ◽

Instability Criterion ◽

Mountainous Area ◽

Soil Slope ◽

Element Analysis ◽

The Stability ◽

Similar Soil

In the construction of mountainous area roads, the similar soil slope is the most common slope form. During the construction, the problem we often meet is how to make the evaluation about the stability of the similar soil slope. The joints exist in the matrix rock, which make great effect on the stability of the slope. The main idea of this article is to analyze the effect of joints and the rain seeped in on the instability of the slope. To solve the problem, the finite element strength reduction theory is taken in this article, and the geotechnical finite element analysis software z_soil is chosen to make the analysis about the instability criterion and the stability in the condition the rain of the similar slope.

Research on the Orthogonal Test of Tunnel Supporting Parameters Based on the Finite Element Strength Reduction Method

10.4028/www.scientific.net/amm.170-173.1533 ◽

2012 ◽

Vol 170-173 ◽

pp. 1533-1537 ◽

Cited By ~ 2

Author(s):

Peng Li He

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Reference Value ◽

Strength Reduction ◽

Surrounding Rock ◽

Original Design ◽

Rock Stability ◽

Parallel Tunnel ◽

The Stability ◽

Element Method

In this thesis, considering the double-hole parallel tunnel engineering with super-small interval, the optimization of designed supporting parameters are studied by the strength reduction finite element method. The calculated safety factor by using the strength reduction finite element method was considered as the index of the tunnel surrounding rock stability, and by using the orthogonal finite element experimental method, the parameters are analyzed and the optimal values of bolt and spry cement are given. The excavation and supporting process under the optimal supporting parameters is simulated, and it indicates that the optimal parameters not only could ensure the stability of the tunnel surrounding rock, but also could decrease the cost of the engineering comparing with the original design project, and there is reference value for analogous engineering.

Three-dimensional strength-reduction finite element analysis of slopes: geometric effects

Canadian Geotechnical Journal ◽

10.1139/t2012-014 ◽

2012 ◽

Vol 49 (5) ◽

pp. 574-588 ◽

Cited By ~ 52

Author(s):

T.-K. Nian ◽

R.-Q. Huang ◽

S.-S. Wan ◽

G.-Q. Chen

Keyword(s):

Finite Element ◽

Slope Stability ◽

Slip Surface ◽

Boundary Effect ◽

Three Dimensional ◽

Strength Reduction ◽

Infinite Length ◽

Surface Geometry ◽

Element Analysis ◽

The vast majority of slopes, both natural and constructed, exhibit a complex geometric configuration and three-dimensional (3D) state, whereas slopes satisfying the assumption of plane strain (infinite length) are seldom encountered. Existing research mainly emphasizes the 3D dimensions and boundary effect in slope stability analysis; however, the effect of complex geometric ground configuration on 3D slope stability is rarely reported. In this paper, an elastoplastic finite-element method using strength-reduction techniques is used to analyze the stability of special 3D geometric slopes. A typical 3D slope underlain by a weak layer with groundwater is described to validate the numerical modeling, safety factor values, and critical slip surface for the 3D slope. Furthermore, a series of special 3D slopes with various geometric configurations are analyzed numerically, and the effects of turning corners, slope gradient, turning arcs, and convex- and concave-shaped surface geometry on the stability and failure characteristics of slopes under various boundary conditions are discussed in detail.

Kajian tentang stabilitas KM. Surya Prima yang dibuat di Desa Borgo, Kec. Tanawangko, Kab. Minahasa

JURNAL ILMU DAN TEKNOLOGI PERIKANAN TANGKAP ◽

10.35800/jitpt.2.1.2015.8330 ◽

2015 ◽

Vol 2 (1) ◽

Author(s):

Gerry Willardoe Kayadoe ◽

Heffry V. Dien ◽

Revols D.Ch. Pamikiran

Keyword(s):

Dynamic Stability ◽

Area Under The Curve ◽

Static Stability ◽

International Maritime Organization ◽

Stability Calculation ◽

Calculation Results ◽

C 30 ◽

The Stability ◽

Parameter Values ◽

The Village

ABSTRACT The stability of a ship is one of the important technical factors in supporting successful fishing operations, and ultimately improving the welfare of fishermen; therefore a study on the stability of KM. Surya Prima had been done in the village of Borgo, District of Tanawangko, Minahasa Regency. Dynamic stability is the stability of the vessel measured by giving a force at the boat to form a certain rocking angle. This stability is expressed as an area under the curve of static stability. Dynamic ship stability calculation results will be compared with the stability criteria according to the International Maritime Organization (IMO) as in Fyson (1985) through the GZ curve. From the comparison it will get the level of dynamic stability of the vessel under study. Dynamic stability parameter values of Surya Prima purse seine vessel were: A (0-300) = 0.1179 m-rad., B (0-400) = 0.1935 m-rad., C (30-400) = 0.07552 m-rad., D (Angle GZmax) = 48 097, E (GZmin) = 0.475 m, F (GM) = 0965 m. Keywords: stability, curve, purse seiner ABSTRAK Kestabilan kapal adalah salah satu faktor teknis penting dalam menunjang sukses operasi penangkapan ikan, dan pada akhirnya akan membantu meningkatkan kesejahteraan nelayan; oleh karena itu telah diadakan penelitian stabilitas KM. Surya Prima di Desa Borgo, Kecamatan Tanawangko, Kabupaten Minahasa. Stabilitas dinamis adalah stabilitas kapal yang diukur dengan jalan memberikan suatu usaha pada kapal sehingga membentuk sudut oleng tertentu. Stabilitas dinamis dinyatakan dalam luas area di bawah kurva stabilitas statis. Hasil perhitungan stabilitas dinamis kapal yang diukur dibandingkan dengan nilai kriteria kestabilan kapal oleh International Maritime Organization (IMO) dalam Fyson (1985) melalui kurva GZ. Dari perbandingan itu akan didapatkan tingkat kestabilan dinamis dari kapal yang diteliti. Nilai parameter kestabilan dinamis kapal pukat cincin Surya Prima adalah sebagai berikut: A (0-300) = 0.1179 m-rad., B (0-400) = 0.1935 m-rad., C (30-400) = 0.07552 m-rad., D (Sudut GZmax) = 48.097, E (GZmin) = 0.475 m, F (GM) = 0.965 m. Kata-kata kunci: stabilitas, kurva, pukat cincin

Stability Analysis of Tunnel Surrounding Rock and Shotcrete Lining and Rock Bolts Based on Strength Reduction Finite Element Method

10.4028/www.scientific.net/amm.90-93.1936 ◽

2011 ◽

Vol 90-93 ◽

pp. 1936-1941

Author(s):

Ying Li ◽

Rong Guan Sun

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Plastic Zone ◽

Constitutive Model ◽

Strength Reduction ◽

Surrounding Rock ◽

Rock Bolts ◽

Safety Coefficient ◽

Characteristic Points ◽

Shotcrete Lining

Based on the practical engineering ,by using the 3D-FEM of elastic-plasticity, a reasonable model for simulation of tunnel excavation and shotcrete lining and rock bolts builds up, surrounding rock using Mohr-Coulomb constitutive model of ABAQUS, lining using Concrete Damaged Plasticity constitutive model, and bolt using elastic-plasticity constitutive model. By using strength reduction finite element method, analysis for safety coefficient of stability of surrounding rock with primary shotcrete lining and rock bolts under the four limit state criteria. It is concluded that the appearance of divergence of the computation may precede by displacement of characteristic points, The safety coefficient of the running-through of the plastic zone of the surrounding rock and the running-through of the plastic zone of the shotcrete and a great amount of rock bolts yielding are less than the divergence of the computation and displacement of characteristic points.