Influencing Factors and Evaluation Criteria of Pile Foundation Settlement in Karst Area

In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundation, the orthogonal simulation tests of pile foundation under 4 different roof thickness and 5 different slope are carried out by using Marc finite element software, and the correction coefficient of vertical partial bearing capacity of pile foundation according to roof thickness and slope is put forward. The test results show that when the thickness of the roof is more than 3 times the pile diameter, the ultimate bearing capacity of the pile foundation tends to be stable, and the value is about 19% when the slope is 45°; the ultimate bearing capacity of the pile foundation decreases gradually with the increase of the slope, and the reduction reaches 29.83% when the slope is greater than 45°. According to the calculation results, the variation law of vertical partial bearing capacity of pile foundation is analyzed, and the calculation formula of standard value of vertical ultimate bearing capacity of pile foundation in steep slope karst area considering both roof thickness and slope is put forward, and the correction coefficients αi and β are put forward.

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Analysis of Factors Affecting Bearing Capacity of Large Diameter Single Piles of Offshore Wind Power under Earthquake Loads

E3S Web of Conferences ◽

10.1051/e3sconf/201913604061 ◽

2019 ◽

Vol 136 ◽

pp. 04061

Author(s):

Yazhou Li ◽

Li Dong

Keyword(s):

Wind Power ◽

Influencing Factors ◽

Pile Foundation ◽

Large Diameter ◽

Horizontal Displacement ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Single Pile ◽

Horizontal Deformation ◽

Offshore Wind Power

The offshore wind turbine single pile foundation structure is simple and easy to install, but in the earthquake environment, large horizontal displacement is easy to occur, which affects the safe operation of offshore wind turbines. For this reason, the bearing characteristics and influencing factors of large-diameter single-pile offshore wind power under earthquake load are analyzed. The Mohr-Coulomb model is used as the model. The ABAQUS is used to construct the large-scale single-pile finite element model of offshore wind power. Loads and analysis of bearing characteristics and influencing factors of large-diameter single-pile offshore wind power under seismic loading. It is found that the increase of pile foundation depth will significantly reduce the horizontal displacement at the top of single pile. After increasing to a certain extent, it has no significant effect on the development of horizontal deformation of large diameter single pile; with the increase of pile diameter and wall thickness, The deformation of large diameter single pile foundation is reduced, but the influence of the pile foundation thickness on the horizontal deformation of the large diame-ter single pile foundation is no longer significant.

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Model Tests of Foundation Bearing Capacity of Sandy Soil and Pile Foundation Bearing Capacity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.113 ◽

2014 ◽

Vol 580-583 ◽

pp. 113-117

Author(s):

Shi Jie Lu ◽

Hua Dong Chen ◽

Wei Chen ◽

Tong Xiang ◽

Xie Feng Hong

Keyword(s):

Bearing Capacity ◽

Sandy Soil ◽

Pile Foundation ◽

Soil Mechanics ◽

Model Tests ◽

Foundation Engineering ◽

Foundation Settlement ◽

Load Bearing ◽

Model Device ◽

Weight Loading

Using self―made model device, researchers studied the characteristics of foundation settlement of sandy soil and pile foundation load―bearing in sandy soil. Through weight loading, researchers analyzed the phenomenon of foundation settlement. Then, researchers embedded friction piles in sand, so as to analyzed pile foundation bearing capacity. The methods and results of the research can provide guidance for teaching of Soil mechanics and foundation engineering.

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A Fuzzy Approach to Assess the Contractor’s Competitiveness

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.3946 ◽

2011 ◽

Vol 71-78 ◽

pp. 3946-3949 ◽

Cited By ~ 1

Author(s):

Na Dong ◽

Jing Zhang ◽

Min Jiu Yu

Keyword(s):

Influencing Factors ◽

Quantitative Evaluation ◽

Evaluation Method ◽

Comprehensive Evaluation ◽

Evaluation Criteria ◽

Qualitative Evaluation ◽

Fuzzy Comprehensive Evaluation ◽

Fuzzy Approach ◽

Fuzzy Comprehensive Evaluation Method ◽

Comprehensive Evaluation Method

A competitive contractor is the guarantee of project’s success, so how to choose a suitable contractor is critical for the owners. However, among the influencing factors considered in the selection, some can be quantitatively evaluated with clear evaluation criteria while others can only be qualitative evaluated so that no specific scores can be obtained. For the above reasons an improved fuzzy comprehensive evaluation method is proposed in which all assessment factors are divided into two categories and are evaluated with different criteria. The method integrates the advantage of quantitative evaluation and qualitative evaluation. Finally it is verified by a case and the result shows that the application of the improved fuzzy approach to choose contractor is effective and reasonable.

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Fracture Failure Risk Analysis of Pressure Pipeline Containing Defects on Pile Foundation Settlement

Volume 3: Design and Analysis ◽

10.1115/pvp2006-icpvt-11-93073 ◽

2006 ◽

Author(s):

Xiang Li ◽

Jinyang Zheng ◽

Yujun Xie

Keyword(s):

Risk Analysis ◽

Failure Probability ◽

Pile Foundation ◽

Moment Equation ◽

Assessment Procedure ◽

Foundation Settlement ◽

Disastrous Consequence ◽

Fracture Failure ◽

Failure Risk ◽

Pressure Pipeline

Pile foundation settlement might cause a disastrous consequence to an in-service pressure pipeline. Flaws, which are unavoidable in the pipeline, lead to reduction of load-supporting capability and service life of the pipeline. So fracture failure risk analysis of in-service pressure pipeline is important in engineering. Failure probability of pipeline due to pile foundation settlement is computed by using the well-known safety assessment procedure R6. Three-moment equation is adopted to compute bending moment in the condition of n piles, where n is the number of piles. A numerical example was presented to illustrate the application of fracture failure risk analysis to determine the failure probability of the pressure pipeline, considering the uncertainties in various internal operating loadings and external forces, flaw sizes, material fracture toughness and flow stress. Furthermore, the failure probabilities of each defect and the whole pipeline were obtained.

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Forestland change and soil erosion in karst watershed under the Grain to Green Project

10.5194/egusphere-egu2020-4456 ◽

2020 ◽

Author(s):

Siwen Feng ◽

Hongya Wang ◽

Hongyan Liu ◽

Chenyi Zhu ◽

Shuai Li

Keyword(s):

Soil Erosion ◽

Influencing Factors ◽

Southwest China ◽

Drainage Basin ◽

Karst Area ◽

Karst Region ◽

Vegetation Growth ◽

The Past ◽

Pixel Scale ◽

River Drainage Basin

<div>With the implementation of the Grain to Green Project, the vegetation growth in karst region in southwest China has increased. In order to explore whether the growth of trees can be sustained after artificial afforestation in karst area and the influence of the forestland change on soil erosion, the WaTEM/SEDEM model was used to simulate the 11 stages of annual soil erosion in the past 33 years in Chongan river drainage basin in Guizhou, and the dominant influencing factors of soil erosion change in the past 33 years were discussed based the pixel scale in this study. The results showed that the forestland increased in a fluctuating way after the conversion project, and the decrease of forestland was mainly caused by drought, especially in the area where the dolomites were distributed. Therefore, the change of forestland caused no significant improvement in soil erosion since the Grain to Green Project.</div><p></p>

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The Maximum Height and Attenuation of Impulse Waves Generated by Subaerial Landslides

Shock and Vibration ◽

10.1155/2018/1456579 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Baoliang Wang ◽

Lingkan Yao ◽

Haixin Zhao ◽

Cong Zhang

Keyword(s):

Influencing Factors ◽

Wave Height ◽

Water Waves ◽

High Speed ◽

Transient Flow ◽

Evaluation Criteria ◽

Maximum Height ◽

Flume Experiments ◽

Orthogonal Experiments ◽

Wave Height Attenuation

High-speed landslides that flow into reservoirs can cause impulsive water waves. To study the characteristics of the maximum impulse wave’s height and its attenuation, 25 sets of flume experiments were conducted using orthogonal theory and 6 main influencing factors were considered. Taking the impulse wave heights as the evaluation criteria and analyzing the 6 influencing factors at 5 different levels, the characteristics of the maximum impulse wave’s height and its attenuations were obtained. Then, statistical relationships between the maximum wave height and the controlling factors were proposed. Then, by combining the continuity equation and the hydrodynamic open channel transient flow movement equation, the process of landslide wave height attenuation was studied, and it was found that the attenuation of the wave is consistent with exponential attenuation. Then, combined with the data obtained from the orthogonal experiments, an attenuation equation for the surge was derived. Finally, the proposed equation was validated by applying it to the landslides that took place along the shore of the Zipingpu reservoir, which were triggered by the Wenchuan earthquake, and the results indicate that the calculated results are very close to the observed results.

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