随着我国国民经济建设的迅猛发展,各种与地质相关的工程项目规模越来越大,以地质体为主体建成的工程规模亦愈来愈大,出现的问题愈来愈复杂,由此引起了许多学者和工程技术人员广泛关注。为此,研究和编写论文过程中贯穿两条主线:一是分析和研究当前地质工程的研究现状及其风险表现形式、风险的特征,二是探讨地质工程项目的风险管理思路及风险评估的方法理论,进行了如下几个方面的探索性研究。(1)对地质工程问题的新认识①地质工程学的研究对象是以地质体为主要工程结构的一类特殊工程,它包括三个基本点:一是地质环境对工程安全稳定性的控制性作用,二是地质灾害治理技术的研究和开发,三是地质灾害的监测与预警。②地质工程学研究的基本思路是以地质条件研究为基础,有针对性地提出合理的工程施工方法、加固治理工程措旌、防灾设计以及灾害的检测预报,其研究的目标是防止地质灾害的发生、保障工程的安全作用,以实现自然系统与工程系统达到最佳耦合状态。③论文认为地质工程项目具有三个基本特性:1)项目立项的艰巨性和复杂性;2)项目是诸多地质学技术的综合反映;3)项目的隐蔽性及其影响的持久性。(2)地质工程项目风险的分析①论文认为地质工程项目风险在时间维度上主要表现为自然系统的客观存在性和人们的认知能力的有限性,在空间维度上主要表现为工程系统作用域或影响区域的风险性,主要表现为:1)风险具有双重来源,引发风险的因素既来自自然界,也来自人类本身;2)风险存在的客观性和普遍性;3)风险的可变性和可利用性;4)风险的多样性和多层次性;5)风险具有可计算性和不可计算性。②根据风险的概率分布规律,结合地质工程项目特点及其风险表现特征,本文将其风险划分为:可规避性、可转移性、可缓解性和可接受性四个等级。(3)地质工程项目风险管理的探讨①论文将地质工程项目风险管理特性归纳为:1)项目参与方比较多,对于不同的利益相关者,他们承担的风险也是不同的;2)风险是有时限的,不同的风险可能存在于项目的某一阶段,其风险具有潜伏期和活动期两大基本特征,风险的承担者也只在这特定的时间内才承担这些风险;3)项目风险管理的目的在于在对地质体的改造过程中不断地预测将会出现的各种风险并制订相应的应急预案。4)项目风险管理是有代价的。②论文将地质工程项目风险管理定义为项目管理者通过对风险的识别、选择相应的手段,以最小的支出,获得最大的安全效果的动态过程。1)、管理流程包括风险的识别与评估、管理的规划、风险的决策与实施风险控制。2)、风险控制措施主要包括组织措施、管理措施、经济措施和技术措施四个方面。(4)地质工程项目风险评估模型的探讨结合地质工程项目管理特性及其管理流程,论文就其项目整个系统风险、决策风险和成本与进度风险进行了如下五个方面的探讨。①项目系统风险的评估。分别从时间维、空间维和目标维三度空间上分析了影响工程项目的风险因子,在确定评价因素、因子的评价等级标准和权值的基础上,运用模糊集合变换原理,以隶属度描述各因素及因子的模糊界线,构造模糊评价矩阵,通过多层的复合运算,最终确定评价对象所属的风险等级。②项目决策风险评估。在分析地质工程项目决策程序和决策科学化原则的基础上,采用离散数学的相关理论、集合论和概率统计的方法,建立了风险型决策的数学模型和决策方案风险的数学模型。③项目承包风险评估。以灰色聚类分析为主体,辅以灰色统计法和AHP法(层次分析法),在确定其风险等级划分的基础上,建立了项目承包风险的评估模型。④成本监测及风险预警。采用新陈代谢GM(1,1)模型对项目的施工成本进行预测分析并建立了施工成本风险监测预警模型。⑤项目进度风险评估。采用采用模糊优选理论与动态网络结构的原理对事先拟定的多种进度计划方案进行计算分析,为科学决策提供依据,建立动态网络模型以更好地对项目的进度风险进行监测和预警。
逆变焊机
Along with the growth of China economic construction, geological-related construction projects are turning larger in scale and locating more complicated problems. The situation has drawn the intention of most of academicians and technical engineers. In the paper, we follow 2 main logic threads: firstly to analyze current research status of geological-related projects, as well as the form and characteristics of its potential risk; secondly to discuss current risk-management mindset and risk-assessment theories adopted in geological engineer projects.1. New acknowledgement to Geological engineering(1)Geological engineering studies projects with major structure of geology based. It contains three basic points: the controlling function of geological environment to the safety and stableness of projects, the studies and developments of geological disaster remediation and geological disaster monitoring and forecasting.(2)Basic principle of geological engineering researches is to reach appropriate construction method, consolidated remediation project measurements, disaster-proof design and disaster forecast based on geological condition studies; the purpose of the researches is to prevent geological disaster, ensure the safety of constructions and perform the best coupling of nature and construction system.(3)The paper believes that geological engineering projects contains three basic characteristics:①Difficulties and complex factors in project setup;②Reflection of multiple geological technologies;(3)Invisibility and sustainability of projects.2. Risk characteristics of geological engineering projects(1)Due to the agnostic and complex character of geological engineering projects, its basic parameter design is quite flexible and subjective:①Dual resources of risks: from nature and human beings;②Rjsk is the combination of objective conditions and subjective cognition;③Changeable and usable risks;④Multiple style and level of risks;⑤Countable and in-countable risks.(2) Considering the probability of risk distribution, the characteristics of geological construction and its risk presenting form, the paper distribute risks into 4 levels of avoidable, transferable, alleviatable and acceptable.3. Discussion of geological engineering project risk management(1)The paper concluded the administrative character of geological engineering projects as below:①Multi-parties: geological engineering constructions are usually implemented by several parties without stable cooperative relations; these parties possess different, sometimes even opposite interest-related concerns;②Time-window-related risk: risk of latent period and active period. Different construction stage consist different risks and the undertaker of the risks burdens the risks only within specific time-window.③Purpose of project risk management is to keep forecasting possible risks and to design related urgent plans.④Project risk management is not free.(2) The paper defines geological engineering project management as a dynamic process that gains the best safety effect with least cost by project administrators’ risk reorganization and measurement choosing.①Management process includes risk recognition and assessment, management plan, risk related decision-making and risk control performance;②Risk control measurements include organization measurement, administrative measurement, economic measurement and technical measurement.4. Building of risk assessment modelCombining geological engineering project management characteristics and its management process, the paper performed discussion to system risk, decision-making risk, as well as cost and process risk from 5 aspects:(1)System risk assessment: analyze risk factors that may potentially affects construction from dimensions of time, space and achievement, based on different weight of assessment ingredients and factors, adopting fuzzy sets transform to describe the fuzzy borderline of different ingredients and factors by subjectiveness, create fuzzy assessment matrix and determine risk level of the subject;(2) Decision making risk assessment: based on analysis to projec decision-making process and the principle of scientific decision-making, adopting theories of discrete mathmatics, set theory and statistical methods to create arethmatic model of decision-making risk and risky decision-making;(3)Sub-contract risk assessment: adopting grey segregation analysis, supported by grey statistics and AHP (analytic hierarchy process) methods to establish project sub-contract risk analysis model.(4)Construction cost management and risk forcast: adoting Information Renewal GM (1,1) Model to predict implementation cost and to create construction cost risk monitoring and forecast model(5)Construction progress risk assessment: firstly, to discuss the progress risk assessment methodology of single project goal based on progress risk factor analysis; secondly, to adopt fuzzy optimization and dynamic mesh structure and analyze pre-set different progress plans to provide support for scientific decision making; as well as to establish dynamic network model to provide better monitoring and forecast for the project progress risk.