Influencing factors and control measures of excavation on adjacent bridge foundation based on analytic hierarchy process and finite element method

ABSTRACT Numerous studies suggest that 80% of accidents in hydrocarbon processing industries are as a result of human factors (HFs). While a lot is known of human factor influence to process accident, the effects of performance influencing factors (PIFs) on human factors in process accidents is not yet well understood. This study examined HFs and PIFs which influences the propagation of undesired occurrences in hydrocarbon processing industries. An illustrative case study of the Tesoro refinery accident was analysed. To affirm consistency in judgments, Analytic Hierarchy Process AHP – a multi-criteria decision-making method was used in identifying HFs and PIFs of critical events. BPMSG AHP computer program was also used to validate results obtained from the manual calculations. Three critical events namely non-routine operations (Event 1), manual manipulation of several isolation block valves (Event 2) and automated start-up operations of Naphtha Hydro-Treating unit (Event 3) were identified. The ranking of PIFs revealed that Procedures, Level of Supervision, Task Characteristics, and Skill Level were major influencing factors to the event. Analysis of human factors revealed that Job Factors had the most significant influence (41%), while the Individual Factors and Organisational Factors had (31%) and (28%) influence respectively. The consistency index (CI) and consistency ratios (CR) of the PIFs were 0.174 and 0.193 for critical Event 1; 0.170 and 0.120 for critical Event 2; and, 0.037 and 0.033 for critical Event 3 respectively. This showed consistency in judgments of the study on PIFs selected for the critical events identified. The Tesoro refinery accident was due to latent organisational and cultural failures.

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Durability Assessment of Lightweight Cellular Concrete in Subgrade by the Method of Analytic Hierarchy Process Combined with Fuzzy Comprehensive Evaluation

Mathematical Problems in Engineering ◽

10.1155/2019/4915870 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Xin Liu ◽

Chengwei Ni ◽

Liye Zhang ◽

Ke Sheng ◽

Baoning Hong

Keyword(s):

Analytic Hierarchy Process ◽

Influencing Factors ◽

Comprehensive Evaluation ◽

Fuzzy Comprehensive Evaluation ◽

Assessment Method ◽

Assessment Model ◽

Analytic Hierarchy ◽

Durability Assessment ◽

Hierarchy Process ◽

Cellular Concrete

The durability of lightweight cellular concrete (LCC) and the corresponding assessment method are studied in this paper to improve the utilization of LCC in subgrade construction engineering. The durability assessment method is established by combining the analytic hierarchy process (AHP) with fuzzy comprehensive evaluation (FCE). The main assessment processes are as follows. Firstly, based on the physical and mechanical properties of LCC, the influencing factors are selected in terms of preliminary design, construction technology, and operation and management after completion of construction. The grading standard of influencing factors is established as well. Secondly, a multilevel assessment model with targets level, criteria level, and indexes level is established. AHP determines the effective weight of the lower level relative to the upper level. The consistency check of the judgment matrix is conducted to prove the rationality of the distribution of influencing factors’ effect weight. Thirdly, the membership function which is suitable for each influencing factor is built to calculate the membership degree. Besides, the practicality and reliability of AHP combined with FCE are demonstrated through a practical engineering case, which is the third section of a highway in Guangdong Province, China.

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Monte Carlo Simulation for Exploring Mechanical Properties of Porous Materials Based on Scaled Boundary Finite Element Method

Applied Sciences ◽

10.3390/app12020575 ◽

2022 ◽

Vol 12 (2) ◽

pp. 575

Author(s):

Guangying Liu ◽

Ran Guo ◽

Kuiyu Zhao ◽

Runjie Wang

Keyword(s):

Mechanical Properties ◽

Finite Element Method ◽

Monte Carlo Simulation ◽

Finite Element ◽

Monte Carlo ◽

Porous Materials ◽

Influencing Factors ◽

Random Models ◽

Scaled Boundary Finite Element ◽

Element Method

The existence of pores is a very common feature of nature and of human life, but the existence of pores will alter the mechanical properties of the material. Therefore, it is very important to study the impact of different influencing factors on the mechanical properties of porous materials and to use the law of change in mechanical properties of porous materials for our daily lives. The SBFEM (scaled boundary finite element method) method is used in this paper to calculate a large number of random models of porous materials derived from Matlab code. Multiple influencing factors can be present in these random models. Based on the Monte Carlo simulation, after a large number of model calculations were carried out, the results of the calculations were analyzed statistically in order to determine the variation law of the mechanical properties of porous materials. Moreover, this paper gives fitting formulas for the mechanical properties of different materials. This is very useful for researchers estimating the mechanical properties of porous materials in advance.

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