This paper compares the performance of critical state constitutive modelling with laboratory triaxial test data from a classic series of tests on reconstituted Weald clay. Critical state models used for predicting the test results include the original Cam-Clay model, Cam-Clay incorporating the planer Hvorslev surface on the dry side of critical and the Modified Cam-Clay model. The purpose of the comparison is to illustrate the dangers of using constitutive relations and models in numerical analyses without a proper understanding of their fundamental assumptions and inherent limitations. It will be shown that Modified Cam-Clay performs satisfactorily under the specific conditions of standard triaxial compression testing and that it fits experimental stress paths closer than the original Cam-Clay model. However, it is of utmost importance to include the Hvorslev state boundary surface on the dry side of critical for both these models if realistic predictions are to be made for heavily overconsolidated soils.
This paper reports on a study of civil engineering students' perception of selected aspects of the experiential learning programme, which is a required component of the National Diploma programme. The findings indicate that the students usually found the work assignments given to them manageable and usually to be relevant to their professional growth. While they usually found there was a link between the courses covered at the technikon and the tasks performed, the former only moderately prepared them for the experiential learning. They rated the overall experiential learning programme as good.
This paper presents a Proposed Method for Dolomite Land Hazard and Risk Assessment for characterising the potential stability of dolomite land, which is based on the Method of Scenario Supposition proposed by Buttrick and Van Schalkwyk (1995). The Proposed Method considers risk as well as hazard and reviews the classification of sites in terms of Dolomitic Area Designations as defined in the National Home Builders Registration Council's Home Building Manual (NHBRC 1999). The Proposed Method requires the evaluation of site geological conditions, provides a deductive framework within which professional judgement must be exercised, and offers a tool for the quantification and management of development risk. The provisions of the Housing Consumer Protection Measures Act (Act 95 of 1998) for the management of risk relating to housing development on dolomitic land are also presented.