The Stability Evaluation and Prospectsabout Environment Engineering Geological in Coastal Zone

MA Xue-ying

(Qingdao University,Qingdao Shandong 266071,China)

1 Research progress

Research of coastal zone starts late in our country,a national comprehensive investigation of coastal zone was begin since 1981[1],and the problems associated with coastal zone also attracted the attention of many scholars.According to the geological environment and geological resources evaluation results,Shi Yujin,etc.[2](2012)combined with Marine functional division of Shanghai preliminary explored the principles and methods of Marine environmental geology function regionalization.In this paper,on the basis of predecessors’s research,we set up fuzzy comprehensive evaluation model,and make the qualitative evaluation of site geological stability of coastal zone environment,which will help the development of coastal engineering,environmental protection engineering.

2 Environment engineering geology stability evaluation in coastal zone

The stability evaluation methods of environment engineering geology in coastal zone.

Researches about environment engineering geology in coastal zone in addition to conventional engineering geology research content,also must to havedeeper understanding of natural Marine environment[3].On the basis of Yan mancun[3],Du Jun,etc.[4]research analysis,build aset of environment engineering geology stability evaluation index system in coastal zone,including the active faults,seismic activities,relief,etc.8 evaluation index,through the index of quantitative grading,weighting and construct the membership function,fuzzy comprehensive evaluation model is constructed.

1）Determination of evaluation index membership degree

Membership functions including normal type,Γtype,type in Dijon,etc.,it’s determined by the distribution of evaluation indexes.According to the results of the fuzzy information of each evaluation index to the single factor evaluation,all of the single factor evaluation constitute evaluation factor set U to the level of stability evaluation set V the fuzzy relationship matrix of R：

V1,V2,V3,V4,V5

V1,V2,V3,V4,V5 are respectively corresponding to different evaluation factors of membership degree value,r1,r2,r3,r4,r5,r6 and r7,r8 represent the active faults,seismic activity,relief degree,formation lithology,bearing capacity of soil,hydrological conditions,the strength of Marine natural environment and human engineering activities these eight kinds of evaluation indexes.

2）Determination of the weights evaluation indexes

The coastal zone environment engineering geology stability evaluation is a problem involving the multi-index comprehensive evaluation.So each weigh evaluation index which weights the weight of each evaluation index weight is also different.Weights reflect the relative importance between different evaluation factors.The determination of each evaluation index on the basis of expert judgment,introduced analytic hierarchy decision-making process and method,structural weights of judgment matrix,and concluded that the weight of each evaluation index value.

A=(a1,a2,a3,a4,a5,a6,a7,a8)

a1,a2,...,a8 represent the active faults,seismic activity,relief degree,formation lithology and bearing capacity of soil,hydrological conditions,Marine natural environment and human engineering activity intensity 8 evaluation index.Each index weight should satisfy the following relations：

3）Fuzzy matrix operations

By establishing the fuzzy relationship matrix R,as well as the right to set A value distribution,you can get A comprehensive evaluation of the results of evaluation units B：

B=A*R=(b1,b2,b3,b4,b5)

Type of"*"is fuzzy transform operator.Evaluation results B based on the evaluation factor set U comprehensive evaluation results,the results of the algorithm on the degrees of membership value are a set of grade.According to the maximum membership degree principle,the maximum membership degree level can be choosed as evaluation unit of hazard geology stability level.

3 Conclusions and prospect

Fuzzy comprehensive evaluation model is effective to solve the environmental engineering geological stability influence factors of complexity and uncertainty and the limitation of stability evaluation classification boundary ambiguity,from qualitative to quantitative,simple and clear,reasonable and objective.According to the actual situation of evaluation of regional comprehensive in-depth research,we should strengthen the development of coastal zone before the investigation and planning,do monitor and manage in the process of coastal zone development and implement regional comprehensive management and control.

［1］Zheng Jimin.China ocean engineering geological research [J].Journal of engineering geology,1994,2(1)：90-96.

［2］Shi Yujin,Yan Xuexin,Fang Zheng.Shanghai coastal zone regional environmental geology function regionalization study [J].Journal of engineering geology,2012,20,30-34.

［3］Yan Mancun,Wang Guangqian,Li Baosheng,etc.Based on the fuzzy mathematics geological environmental regionalization of guangdong coastal land[J].Journal of geography and the study,2000,16(4)：41-48.

［4］Du Jun,Li Peiying,etc.China’s coastal zone hazard geology stability zoning[J].Journal of natural disasters,2008(4)：2-6.