scholarly journals Probability Integral Method in the Influence of Ground Settlement on a Certain Construction Land

CONVERTER ◽  
2021 ◽  
pp. 407-416
Author(s):  
Junda Lyu, Jiacheng Gao, Chuanrong Xue
Keyword(s):  
Surface Displacement ◽  
Probability Method ◽  
Ground Settlement ◽  
Horizontal Deformation ◽  
Potential Threat ◽  
Construction Land ◽  
Absolute Value ◽  
Probability Integral Method ◽  
Calculation Results ◽  
Integral Probability

There is a potential threat of geological hazards in the construction land adjacent to a mined-out area on the west side. To accurately determine the degree of influence of the mined-out area in this area, this article has collected and sorted out five reports on a gypsum mine since 2010, combined with various parameters in the relevant reports, and used the integral probability method. Quantitatively calculate the surface displacement value, surface tilt value, absolute value of horizontal deformation and the maximum settlement value in the goaf area. The actual calculation results show that the construction land here is not affected by the goal of the gypsum mine.

Generalized definition and application of tolerance

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6807-6814
Author(s):  
Hao Jianjun ◽  
Wang Youli ◽  
Wang Xiaohui
Keyword(s):  
Error Compensation ◽  
Extreme Values ◽  
Probabilistic Method ◽  
Tolerance Analysis ◽  
Machining Process ◽  
Negative Number ◽  
Absolute Value ◽  
Calculation Results ◽  
Relationship Of ◽  
Dimensional Homogeneity

Tolerance with upper deviation less than lower deviation is defined as virtual tolerance; the dimension between two extreme values required with tolerance (virtual tolerance) is expressed by a set. The changed characteristics of the set range when the tolerance value is continuously reduced from positive to negative are explored. The nature of virtual tolerance is that the absolute value of virtual tolerance is the error compensation amount, and the dimension between two extreme values is the error compensation range. On the basis of the concept of positive and negative number, the theory of dimensional homogeneity, the existing conditions of the general formula of the dimensional chain, the accuracy of the calculation results of tolerance, and so on, the concept of virtual tolerance and its relationship of unity of opposites with tolerance are proposed. Based on the concept of virtual tolerance, analysis and calculation processes of various assembly dimensional chains are unified, and general formulation of calculating the range of false waste is established, and the method of determining the range of false waste by using probabilistic method in machining process is deduced.

Applications of a Compound Distribution on Estimating Wind and Wave Parameters for Fixed Platforms Design

2006 ◽  
Author(s):  
Sheng Dong ◽  
Jinjin Ning
Keyword(s):  
Joint Probability ◽  
Structural Response ◽  
Extreme Value Distribution ◽  
Probability Method ◽  
Base Shear ◽  
Extreme Wind ◽  
Compound Distribution ◽  
Calculation Results ◽  
Extreme Wind Speed ◽  
Return Value

Based on the hindcast data of 21 storm processes, a Poisson bivariate Logistic extreme value distribution is proposed to estimate the joint probability of extreme wind speed and extreme significant wave height in the storms, the frequency of which can be described by a Poisson distribution. In order to calculate the structural response of an ocean platform, such as base shear, three methods are utilized, namely (I) traditional univariate frequency analysis method; (II) base shear return value method; (III) wind-wave joint probability method. Calculation results show that the proposed statistical model is suitable for the design of fixed platforms in the storm-influenced area.

scholarly journals The Ground Settlement and the Existing Pipeline Response Induced by the Nonsynchronous Construction of a Twin-Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shicheng Sun ◽  
Chuanxin Rong ◽  
Houliang Wang ◽  
Linzhao Cui ◽  
Xin Shi
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Construction Process ◽  
Ground Settlement ◽  
Three Dimensional Model ◽  
Relative Stiffness ◽  
Twin Tunnel ◽  
Calculation Results ◽  
Negative Impacts ◽  
Final Settlement

Shielding tunnel construction always has negative impacts on the surrounding buildings. Because of repeated disturbances caused by the construction, more attention should be paid to the impacts of the nonsynchronous construction of a twin-tunnel. In this research, a three-dimensional model was established to simulate the construction process of a twin-tunnel in a section of the Hefei No. 4 metro line, and the calculation results were validated with the measured settlement data. Based on the model, the ground settlement and the existing pipeline responses were studied in detail. The results showed that, after the first tunnel (FT) construction, the settlement curves conformed to a Gaussian distribution. Additionally, after the second tunnel (ST) construction, the final settlement curves were no longer completely symmetrical. The influences of the twin-tunnel space and the pipeline-soil relative stiffness on the settlements were further studied. The results showed that the final settlement curves of the ground surface and the pipeline were mainly W-shaped, U-shaped, and V-shaped. As the twin-tunnel space increased and the pipeline-soil relative stiffness decreased, the settlement curve gradually changed from V-shaped to W-shaped. C was defined as the ratio of two maximum settlements in the W-shaped settlement curve. As the space increased, C started to decrease from 1 and then increased to 1.

Research on Soil Deformation due to Pile Jacking in Saturated Soil

2012 ◽  
Vol 256-259 ◽  
pp. 445-449
Author(s):  
Rui Cai Wang ◽  
Jian Yong Shi ◽  
Ning Zhu
Keyword(s):  
Displacement Field ◽  
Radial Displacement ◽  
Soft Soil ◽  
Surface Displacement ◽  
Vertical Surface ◽  
Theoretical Formula ◽  
Construction Process ◽  
Changing Trends ◽  
Calculation Results ◽  
Theory Calculation

According to the theoretical formula of compacting displacement field due to jacked pile in semi-infinite soil, calculation of displacement field produced during construction process of precast pile was carried out. And the changing trends of radial displacement with depth of pile penetrating, the maximum radial displacement with normalized distance r/D and vertical surface displacement with normalized distance r/D were analyzed in this paper. Then the Comparison between theory calculation results and the field test data was presented. The results show that the theoretical formula will fit with the actual situation of the site, when the soft soil properties around the pile are homogeneous and saturated. The further solving of compacting displacement field due to pile jacking was put forward.

Research on Ground Settlement due to EPB Shield

2011 ◽  
Vol 105-107 ◽  
pp. 1276-1279
Author(s):  
Zhi Gang Yan
Keyword(s):  
Numerical Experiments ◽  
Three Dimensional ◽  
Surface Displacement ◽  
Surface Settlement ◽  
Ground Settlement ◽  
Balance Condition ◽  
Grouting Pressure ◽  
Working Face ◽  
Epb Shield

The surface settlement is affected by many factors due to EPB shield. This paper takes the shield construction of Guangzhou Metro Line 5 as an example, carries out three dimensional numerical experiments on the ground settlement rule. The result indicates that soil warehouse pressure and the efficiency of grouting is important factors of the surface displacement. To increase grouting pressure and shorten the grouting time can reduced the ground settlement in effective. With the increase the soil warehouse pressure, the settlement behind the working face is reduced and the front working face is increased. When the soil warehouse pressure is at the over balance condition, the raising ground is increased and the settlement is reduced. The value of settlement is much larger than the value of raising. So to increase the soil warehouse pressure is another effective method to reduced the ground settlement on the premise that the front soil body of shield does not be destroy.

Research on Stability in Metro Tunnel Constructing with Shallow Buried Covered Excavation in Loose Sand Layers

2012 ◽  
Vol 594-597 ◽  
pp. 1240-1244
Author(s):  
Shen Gang Li ◽  
Wen Zhao ◽  
Xiao Li Cai ◽  
Yin Fu Ma ◽  
Lu Zhang
Keyword(s):  
Numerical Calculation ◽  
Side Wall ◽  
Tunnel Construction ◽  
Loose Sand ◽  
Ground Settlement ◽  
Single Side ◽  
Calculation Results ◽  
Metro Tunnel

For subway tunneling in urban underground, high safty of construction is needed.However, the safty and rationality of excavating plan are forecasted difficultly because of consealment. Based on the Zhang-Shen tunnel construction of Shenyang subway, bench method, single side-wall heading excavation method and CD excavation method are numerical simulated; according to the numerical calculation results and the constructing process, bench method is adopted; the ground settlement caused by excavation monitored during excavating is in the allowed range and the tunnel is safe during excavating.

Effect of Modified Sludge on the Particles Flocculation and Slurry Stability in the Co-slurry of Sludge and Petroleum Coke

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Meng Liu ◽  
Xiaobin Zhang ◽  
Liang Zhao
Keyword(s):  
Energy Consumption ◽  
Zeta Potential ◽  
Petroleum Coke ◽  
Reflectance Measurement ◽  
Absolute Value ◽  
Calculation Results ◽  
The Absolute ◽  
The Stability ◽  
Shearing Energy ◽  
Slurry Stability

Abstract Sewage sludge modified by Ca(OH)2 and Fe2(SO4)3 were used as make the slurry with petroleum coke, and changes in the size distribution and a total number of particles in the slurry were determined by Focused Beam Reflectance Measurement (FBRM) to explore the particles flocculation mechanism. In addition, the structural strength of petroleum coke sludge slurry (PCSS) was calculated by two mathematic models to illustrate the how the sludge improves the stability of PCSS. The results indicated that the absolute value of the Zeta potential of PCSS increased with the sludge addition and that PCSS stability improved. However, the absolute value of the Zeta potential decreased and the stability declined after the sludge was modified by Fe2(SO4)3 and Ca(OH)2. Petroleum coke particles were wrapped by sludge flocs, and small particles flocculated during their co-slurry process to form a spatial network structure, effectively prevented the settlement of petroleum coke particles and ultimately improved the stability of slurry. The calculation results obtained by the two mathematic models reveal that the shearing energy consumption per-unit-quality of PCSS using raw sludge is twice or thrice than that of PCWS. However, energy consumption was reduced after the sludge was modified by Fe2(SO4)3.

Study on Determining Method of Surface Movement Parameters Based on MATLAB

2012 ◽  
Vol 170-173 ◽  
pp. 2876-2879
Author(s):  
You Feng Zou ◽  
Hua Bin Chai
Keyword(s):  
Curve Fitting ◽  
Surface Displacement ◽  
Mapping Function ◽  
Measured Data ◽  
Mining Subsidence ◽  
Ground Movement ◽  
Surface Movement ◽  
Probability Integral Method ◽  
Practical Engineering ◽  
Movement Parameters

It is difficult to accurately calculate the predicting parameters of surface displacement of mining subsidence. Based on the measured data of the ground movement observation station in North China, The probability integral method is taken as mathematical model of Surface movement parameters fitting, the curve-fitting of the measured data is carried out by using Matlab’s efficient data processing and mapping function, thus it becomes easy to obtain accurate predicting parameters of mining subsidence. By comparing the measured data with the curve-fitting results, the research shows that the fitting results based on Matlab is more accurate, and meet the requirements of practical engineering. It is important and practically significant to improve the predicting accuracy of mining subsidence, give scientific and rational guidance to mining under the buildings, railways and water bodies.

scholarly journals Study on Surface Grouting Reinforcement Effect of Small Clear Distance Tunnel in Soil-rock Composite Stratum

2021 ◽  
Vol 276 ◽  
pp. 01004
Author(s):  
Lu-qiang Peng ◽  
Shi-hai Chen
Keyword(s):  
Elastic Modulus ◽  
Numerical Calculation ◽  
Calculation Model ◽  
Surface Settlement ◽  
Reinforcement Effect ◽  
Tunnel Excavation ◽  
Absolute Value ◽  
Calculation Results ◽  
Clear Distance ◽  
Grouting Reinforcement

Based on the Yingxiongshan tunnel project in Jinan, a numerical calculation model of tunnel excavation considering the surface grouting reinforcement effect of soil-rock composite stratum is established, and the effects of elastic modulus and grouting width of grouting reinforcement zone on tunnel stability are studied. and the research results are applied to the supporting project to verify the rationality of the numerical calculation results. The results show that grouting reinforcement can effectively control the deformation of surrounding rock and supporting structure, and the absolute value of surface settlement is negatively correlated with grouting width and elastic modulus. The surface settlement value is not sensitive to the change of the width of grouting reinforcement zone, but is sensitive to the change of elastic modulus.

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