室内土質試験結果の評価とその信頼性

This paper describes some potential difficulties in the evaluation of laboratory test results．The effect on test results of the technique of individual engineers in sampling and testing procedures have been investigated．Considerable differences were found in physical index tests，oedometer tests and unconfined compression tests．This also seems to be due to the magnitude of sampling disturbance during investigations．Reliability of the analytical results derived from laboratory tests were also investigated．
In engineering practice，natural soils have intermediate properties between cohesive soils and cohesionless soils and thus comprise a group of intermediate soils．Such soils，with the engineering properties half way between those of clays and sands，have both favourable and unfavourable characteristics of cohesive and cohesionless soils．It is often difficult to judge to which type a particular soil belongs．These topics are reviewed and discussed in detail based on experimental data．
Finally，a simple application of geochemistry is introduced（sulfur，nitrogen and organic carbon concentration），which investigates the relationship between sedimentary environments and geotechnology．