大地工程資料品質與專業判斷認知-以鑽探報告為例

Abstract

大地工程師的專業，即與大地為伍，瞭解大地的特性，特別是其相關的物理性質及力學性質，並利用力學原理搭配工程經驗進行設計。 在大地工程師任務中看似最簡單但實際上最關鍵的部分莫過於利用其專業，由現有的實驗數據及相關的地質資料提供一可靠的判斷結果，以供後續設計者參考。然而大地工程所包含的不確定性，除了環境、材料、試驗及人為所導致各種數據資料的不確定性之外，大地工程師的專業判斷本身也隱含了不確定性。 本研究針對大地工程中鑽探報告的資料品質及專業判斷認知進行研究調查，透過問卷調查及專家訪談模式，蒐集業界在面對鑽探報告中有關資料品質與專業判斷的看法及建議。由調查結果統計分析，以了解大地工程師對大地工程調查資料品質的認知及了解大地工程師在分析鑽探報告過程中面對問題的處理態度及解決方法。 調查分析結果顯示，大地工程師對於資料品質的認知，確實受到諸多不確定性的因素所影響。大地環境的不確定性，是造成工程師對資料不信任最主要的因素；而就工程師的層面而言，其本身經驗及專業上的差異是對資料品質認知的關鍵因素。至於大地工程師的專業判斷並沒有絕對的對與錯，重點在於其所提出的判斷對工程目的、經濟性、安全性合理與否。

One of the most important tasks of geotechnical engineers is to provide geotechnical information of a site for later design and construction. Geotechni- cal engineers rely on readily available knowledge on the site and data from field investigations to provide such information. In the process of gathering informa- tion and production of a site investigation report, geotechnical engineers have to make a lot of use of professional judgment. The major sources of the uncertainty which forces the engineers to exercise judgment are the complexity of the geological conditions and the heterogeneous nature of the geomaterials. On the other hand, the uncertainty further accumulates when the geomaterials go through in-situ tests, sampling, handling and transportation of the samples, and laboratory tests. Engineers who design with the parameters summarized in the reports seldom know the degree of uncertainty of these parameters. Even the geotechnical engineers that produced the report may not sure about the degree of uncertainty. The objective of this research is to study the perception of engineers on quality of information produced in various stages of the geotechnical investigation. Questionnaires were sent to practicing civil engineers, especially, geotechnical engineers. The results show that the average confidence level of the participants on information quality is low. The major factors affecting the confidence level of individual participants are their major fields of work and years of experience. The least and the most experienced engineers tend to have higher level of confidence. In addition, the results show that quality assurance and quality control measures are either absent or not followed in all stages of the site investigation program in most cases.