Mechanical Properties of Interface Between Soil-Macadam Aggregate and Concrete Pile

2011 ◽  
Vol 368-373 ◽  
pp. 230-233 ◽  
Author(s):  
Shao Jun Li ◽  
Fan Zhen Meng ◽  
Jing Chen ◽  
Hong Min
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Safety Evaluation ◽  
Friction Angle ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Direct Shear Tests ◽  
Concrete Pile ◽  
Shearing Strength ◽  
Reinforcement Design

The mechanical properties of interface between soil-macadam aggregate and anti-sliding concrete pile are very important for the reinforcement design and safety evaluation of accumulative landslide in the reservoir area of Three Gorges. Soil-macadam aggregate is a complex geomaterial whose properties are totally different with soil or rock. Based on a practical landslide suffering the influence of reservoir water level change and seasonal rainfall, a series of direct shear tests are conducted to investigate the interface mechanical properties between soil-macadam aggregate and concrete pile. Accordingly, the relationship between shear strength parameters and water contents and macadam ratios is presented. The change characteristics of mechanical properties of interface are discussed. The results indicate that shearing strength, inner friction angle and cohesion decrease with less water content. However, as the increment of macadam ratios, the cohesion will decrease gradually, but the shear strength and inner friction angle of interface decrease firstly and then increase after a critical value, the change trend obeys parabolic relation.

Dam Safety Reliability Analysis Based on Artificial Neural Network

2011 ◽  
Vol 255-260 ◽  
pp. 3620-3625
Author(s):  
Hai Wei ◽  
Hua Shu Yang ◽  
Liang Wu ◽  
Yue Gui
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Water Level ◽  
Reliability Index ◽  
Safety Evaluation ◽  
Mathematic Model ◽  
Dam Safety ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Artificial Neural

There are many factors, such as climate, flood, material, geology, structure, management, to influence dam safety. So dam safety evaluation, involving many fields, is very complicated, and very difficult to establish mathematic model for assessment. Artificial Neural Network (ANN) has many obvious advantages to deal with these problems influenced by multi-factor, consequently is widely used in engineering fields. This paper considered water level, temperature, main factors influencing dam deformation, as random variables, employed ANN and statistical model to establish performance function of dam hidden trouble deformation and abnormal deformation. Then reliability theory was used to analyze dam safety reliability and sensitivity. The results show that temperature has great effect on probability of dam hidden trouble deformation and abnormal deformation than reservoir water level, due to great variability of temperature. Change of Reliability index of dam is contrary to reservoir water level. Temperature, especially average temperature in 10 days and 5 days, has great effect on sensitivity of reliability index than water level.

Study on In Situ Shearing Strength Test for the Retaining Wall Bottom in a Bank Revetment Project

2012 ◽  
Vol 214 ◽  
pp. 333-337
Author(s):  
Guang Zhang ◽  
Jun Rong Ma ◽  
Jing Xi Chen ◽  
Hua Lin Zhou ◽  
Dong Hua Wang
Keyword(s):  
Shear Strength ◽  
Retaining Wall ◽  
Friction Angle ◽  
Strength Test ◽  
Composite Foundation ◽  
Undisturbed Soil ◽  
Shear Strength Test ◽  
Geological Conditions ◽  
Shearing Strength

To obtain the necessary shear strength parameters of the retaining wall bottom in a bank revetment project, in-situ shearing strength test must be conducted. There are 3 kinds of foundations. One is undisturbed soil foundation, and the other two are composite foundations. Due to the limited of the engineering conditions, each kind of foundation has prepared one specimen only. So the single shearing strength test can't separate cohesion c and friction angle φ. To solve this problem, a method which is a combination of shear strength test and sliding strength test is used. Sliding strength test is carried on specimens that have already failed after shearing strength test. This test is carried in wet conditions and cohesion values and friction angle values are obtained. In addition, the influence of the processing of composite foundation to equivalent friction coefficient is analyzed. Test result can be referenced by bank revetment projects which have similar geological conditions.

Experimental Study of the Shear Strength of Cobalt-Rich Crusts

2013 ◽  
Vol 419 ◽  
pp. 576-580 ◽  
Author(s):  
Hong Yun Wu ◽  
Zheng Chen
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Internal Friction ◽  
Empirical Formula ◽  
Laboratory Testing ◽  
Friction Angle ◽  
Strength Test ◽  
Strength Parameter ◽  
Shearing Strength

The shear strength parameter of cobalt-rich crusts can be used to design cobalt-rich crusts mining head. The shearing test of cobalt-rich crusts sample was done with different angle shearing testing apparatus.Firstly, the cobalt-rich crusts sample with the size of 50mmx50mmx50mm cube was clamped in the variable angle plate.Secondly, the sample ware loaded till to be damaged. Lastly,the damaged load were recorded at the degree of 50, 60 and 70 to establish their shearing strength and normal stress empirical formula.According to the testing result, its cohesion and internal friction angle parameters are respectively 0.275MPa and 54.43 degree. Restricted by the number of samples and limited by laboratory testing,in-situ shearing strength test should be carried out to improve the proposed empirical formula.

scholarly journals Improving Shear Strength Parameters of Sandy Soil using Enzyme-Mediated Calcite Precipitation Technique

2018 ◽  
Vol 20 (2) ◽  
pp. 91 ◽  
Author(s):  
Heriansyah Putra ◽  
Hideaki Yasuhara ◽  
Naoki Kinoshita ◽  
Erizal . ◽  
Tri Sudibyo
Keyword(s):  
Shear Strength ◽  
Sandy Soil ◽  
Friction Angle ◽  
Soil Improvement ◽  
Soil Mass ◽  
Shear Strength Parameters ◽  
Calcite Precipitation ◽  
Strength Parameters ◽  
Direct Shear Tests ◽  
Potential Applications

Several methods have been established for their various potential applications as soil improvement technique, and recently the application of grouting technique using biological process have been proposed. This study discussed the applicability of enzyme-mediated calcite precipitation (EMCP) in improving the shear strength parameters of sandy soil.  In this study, soil specimens were prepared and treated with the grouting solutions composed of urea, calcium chloride, magnesium sulfate and enzyme of urease. Evolutions in the cohesion and internal friction angle of the improved soil were examined through the direct shear tests. The presence of the precipitated materials, comprising 4.1 percent of the soil mass of the treated sand, generated a cohesion of 53 kPa. However, contrary to the improvement of cohesion, the friction angle is relatively constant. It indicated that the application of the EMCP technique has no significant impact on the friction angle

scholarly journals Comparative Study between Silica Fume and Nano Silica Fume in Improving the Shear Strength and Collapsibility of Highly Gypseous Soil

2020 ◽  
Vol 27 (1) ◽  
pp. 72-78
Author(s):  
Ahmed Al-Obaidi ◽  
Marwa Al-Mukhtar ◽  
Omar Al-Dikhil ◽  
Saeed Hannona
Keyword(s):  
Shear Strength ◽  
Silica Fume ◽  
Friction Angle ◽  
Engineering Properties ◽  
Nano Silica ◽  
Direct Shear Tests ◽  
Apparent Cohesion ◽  
Gypsum Content ◽  
Wet Condition ◽  
Gypseous Soil

Soils with highly gypsum content signify known as soils that exhibit collapsibility and sudden failure when being submerged to wetting. Many of the constructions built on this soil showed cracked and/or collapsed at some parts as these soils immersed or leached with water. The utilization of extremely fine materials, for example, Microscale or Nanoscale, is generally utilized these days. This research compared the use of Silica fume (SF) (micro material) and Nano Silica fume (NSF) (Nanomaterial) to explore the capability of these very fine materials to mend the shear strength and collapsibility properties of highly gypseous soils. The soil as Poorly Graded Sand (SP) was used, with a gypsum amount equal to 62%. A succession of direct shear tests and double odometer tests were carried on dry and submarined specimens of soil at various percentages of SF and NSF. The obtained results indicate that mixing the highly gypseous soils with SF or NSF improved the engineering properties of these soils, especially for the wet condition. The average increment in apparent cohesion when adding SF (5-20) percentage varies between (140-310) % in dry soil and (20-40) % in soaked soil. Same results obtained when mixing the gypseous soils with (1-5) % of NSF. Also, the Nanomaterial provided an improvement of the friction angle in dry and submerged cases respectively. Considering that, the SF gives adverse results upon the friction angle of the soil. The SF and the NSF both condensed the dangers of gypseous soil collapsibility. Consequently, the use of NSF can be assertively suggested to improve the engineering characteristics of highly gypseous soils when compared with SF, where only mixing of 3% of NSF gives the best results.

Mechanical Properties of Fly Ash-Slag-Dredged Silt System Stimulated by Alkali

2013 ◽  
Vol 807-809 ◽  
pp. 1140-1146 ◽  
Author(s):  
Yi Xuan Chen ◽  
Xiu Li Sun ◽  
Zhi Hua Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Fly Ash ◽  
Construction Materials ◽  
Xrd Analysis ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shear Tests ◽  
X Ray ◽  
Direct Shear Tests

The objective of this work is to investigate the stimulation effect of the addition of alkali on the fly ash and slag for stabilizing dredged silt. Based on the test results, a viable alternative for the final disposal of dredged silt as subgrade construction materials were proposed. For this purpose, several mixtures of dredged silt-fly ash-slag and alkali were prepared and stabilized/solidified. In this system, fly ash and slag were used as hardening agents (solidified materials) of dredged silt and alkali was used as activator of fly ash and slag. The shear strength of the mixture was tested by several direct shear tests. Furthermore, X-Ray Diffraction (XRD) analysis was used to determine the hydration products of the system. The specimens were tested in order to determine the shear strength changes versus hydration time and the alkali content. It is indicated that mechanical properties of solidified silt are improved significantly by addition of fly ash and slag stimulated by alkali.

scholarly journals Estimation of the shear strength of a coarse soil with high fines content by parallel gradation method

2019 ◽  
Vol 92 ◽  
pp. 06001
Author(s):  
N'guessan MoÏse Kouakou ◽  
Olivier Cuisinier ◽  
Farimah Masrouri ◽  
Emmanuel Lavallée ◽  
Tangi Le Borgne
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Friction Angle ◽  
Granular Soils ◽  
Standard Laboratory ◽  
Fines Content ◽  
Initial Soil ◽  
Coarse Soil

The determination of the mechanical properties of soils containing particles larger than the allowable size of standard laboratory equipments is complex. It is indeed necessary to remove the coarsest fraction to carry out the tests. This scalping poses a problem of reliability of the results at the scale of the structure. Parallel gradation is the method commonly used for estimating the shear strength of heterogeneous granular soils from tests on their finer fraction. However, the effect of high fines content on the estimation of shear strength by this method is not well understood. The results of this study show that the parallel gradation method can predict the friction angle of the initial soil with high fines content when the modelled soil has a similar skeleton as the initial soil. However, the cohesion of the initial soil is overestimated.

Stability of No 7 Landslide Located at Ciha Gorge under the Condition of Reservoir Water Level Rise

2011 ◽  
Vol 368-373 ◽  
pp. 1482-1486
Author(s):  
Yan Hui Song ◽  
Ying Wang ◽  
Min Qi Huang
Keyword(s):  
Shear Strength ◽  
Water Level ◽  
Slip Band ◽  
Water Pressure ◽  
Work Conditions ◽  
Stability Factor ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Stability Calculation ◽  
The Stability

Engineering geology characteristics of No. 7 landslide located at Ciha Gorge is described and shear strength of the slip band soils is determined. Based on the above, unbalanced pushing force method is used to calculate the stability factor of the landslide the under different work conditions. It shows that the influence of the reservoir water level rising on the No. 7 landslide mainly includes two points: (1) water makes the shear strength of slip band soils reduced and thus result in the reduction of the stability factor; (2) the rising of reservoir water level also exerts water pressure to the surface of landslide body, and this is beneficial to landslide stability. Calculation results show that with the rising of reservoir water level the stability factor will experience beginning’s reducing followed by later increasing. The minimum stability factor in the process of impounding is 1.05 and it will be 1.08 when reservoir water level reaches to normal impounded level. This shows that No. 7 landslide will maintain elemental stability status in the all process of impounding.

Experimental Study on Shear Behavior of Short-Fill-Age MSW

2010 ◽  
Vol 113-116 ◽  
pp. 479-483
Author(s):  
Li Sha Ma ◽  
Huan Li Wang ◽  
Wei Wang ◽  
Zheng Wen Zhang
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Friction Angle ◽  
Exponential Model ◽  
Hyperbolic Model ◽  
Displacement Curve ◽  
Shear Tests ◽  
Direct Shear Tests ◽  
Cohesion Force ◽  
Coulomb Criterion

Mechanical behavior of municipal solid waste (MSW) is important to geo-environment engineering, and it is necessary to properly understand it. Laboratory direct shear tests were conducted on MSW with 3 short fill ages, namely 1d, 4d and 7d. Three different densities were taken into accounted in each fill age. Experimental data show that MSW’s shear failure still satisfies the Mohr-Coulomb criterion. As to bigger density, shear strength of MSW increases within 1-7d fill age. When density becomes smaller, its shear strength increases within 1-4d fill age but decreases within 4-7d fill age. With fill-age developing, friction angle of MSW increase monotonously, but cohesion force of it first increases and then decreases. Experimented shear stress-displacement curve of MSW can not be well fitted by either hyperbolic model or exponential model. This experimental research is helpful for design and numerical simulation of corresponding MSW landfill.

Study on the Effect of Water Content on Shearing Strength Parameters of Unsaturated Loess

2014 ◽  
Vol 638-640 ◽  
pp. 585-588 ◽  
Author(s):  
Si Zhong Qian
Keyword(s):  
Internal Friction ◽  
Water Content ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Direct Shear ◽  
Strength Parameters ◽  
Direct Shear Tests ◽  
Micro Particles ◽  
Shearing Strength ◽  
Unsaturated Loess

This paper experiments on typical Malan loess, performs consolidated quick direct shear tests under different water contents by conventional direct shear apparatus, then analyzes the effects of water content on shearing strength parameters, namely cohesion and internal friction angle. The results show that cohesion decreases linearly as the water content increasing, and the relation could be obtained by data fitting. However, internal friction angle keeps basically stable with the increase of water content. Finally, based on the force analysis for micro particles, the changing rules of cohesion and internal friction angle with water content were deeply explained.

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