Risk Analysis of Shrink and Expansion for Expansive Soils and Improved Expansive Soils in the Xinqiao Airport Runway of Hefei

2011 ◽  
Vol 90-93 ◽  
pp. 1307-1312 ◽  
Author(s):  
Ming Wu Wang ◽  
Shuai Qin ◽  
Peng Hua

Risk analysis of shrinking and swelling of expansive soils and improved expansive soils with lime (IESL) for airport runway projection is a complex uncertainty problem. To select the rational foundation treatment plan and ensure the safe operation of runway, herein combined with the features of expansive soils in the runway area of Xinqiao international airport of Hefei, a novel risk analysis method was proposed to classify shrinkage and swell of expansive soils and IESLs by means of coupling set pair analysis with stochastic simulation of triangular fuzzy numbers. A function of six elements connection number was introduced to depict hierarchy and fuzziness of membership between the evaluation sample and the classification standard. Moreover, triangular fuzzy numbers simulated by a stochastic simulation method were presented to specify the component coefficients of discrepancy degree. Then a risk analysis model was described to calculate reliable degree corresponding to a confidence interval. Finally, comparisons of shrinkage and swell for foundation treatment plans of different lime content were conducted. The results will provide basis for the risk design and risk management of runway project on the expansive soils.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Handan Akyar

Ordering and ranking fuzzy numbers and their comparisons play a significant role in decision-making problems such as social and economic systems, forecasting, optimization, and risk analysis problems. In this paper, a new method for ordering triangular fuzzy numbers using the Nagel point of a triangle is presented. With the aid of the proposed method, reasonable properties of ordering fuzzy numbers are verified. Certain comparative examples are given to illustrate the advantages of the new method. Many papers have been devoted to studies on fuzzy ranking methods, but some of these studies have certain shortcomings. The proposed method overcomes the drawbacks of the existing methods in the literature. The suggested method can order triangular fuzzy numbers as well as crisp numbers and fuzzy numbers with the same centroid point. An application to the fuzzy risk analysis problem is given, based on the suggested ordering approach.


Author(s):  
EMRAH AKYAR ◽  
HANDAN AKYAR ◽  
SERKAN ALİ DÜZCE

The ranking and comparing of fuzzy numbers have important practical uses, such as in risk analysis problems, decision-making, optimization, forecasting, socioeconomic systems, control and certain other fuzzy application systems. Several methods for ranking fuzzy numbers have been widely-discussed though most of them have shortcomings. In this paper, we present a new method for ranking triangular fuzzy numbers based on their incenter and inradius. The proposed method is much simpler and more efficient than other methods in the literature. Some comparative examples are also given to illustrate the advantages of the proposed method.


2011 ◽  
Vol 261-263 ◽  
pp. 1329-1335 ◽  
Author(s):  
Ming Wu Wang ◽  
Kang Ge ◽  
Da Rong Zhu

Foundation treatment of expansive soils is a complex worldwide problem. Herein engineering behaviors of expansive soils and improved expansive soils with lime (IESL) in the runway area of Xinqiao international airport of Hefei were investigated by means of laboratory experiments and field tests. It was concluded that the expansive soils of mean plasticity index 24.2, and optimum moisture content of 16% in the engineering area, behaved weak and medium expansive potential. The plastic index of improved expansive soil of 7% lime mixed indoor and of 8% lime incorporated on site dropped to 20 and 13. At the same time, the free swelling ratios of IESL reduced up to 6.31 % and 3% relative to 46.5% of expansive soil, and the swelling pressure also decreased from 67.5 kPa to 4.05 and 11.28 kPa, respectively. The mean unconfined compression strength of improved expansive soil of 7 % lime on site was 853 kPa, 71% stronger of that of expansive soils. And the soil response modulus was up to 235.2 MN/m3, 9 times of expansive soils. It was also found form the immersion tests on site that the swell value of IESL was only 30% at most of expansive soils at the same depth. These results indicate that the compacted IESLs have a good bearing capacity, strength and water stability, so the engineering behaviors of IESLs are much better than those of expansive soils, and prove that the modification plan, expansive soils incorporated 7% lime on site could meet the design requirements.


2018 ◽  
Vol 9 (11) ◽  
pp. 1717-1727
Author(s):  
Ajay Minj ◽  
Pathinathan T.

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