A Study of The Logarithm of Time Fitting Method for Consolidation Test by Measuring Pore Water Pressure

• Main Authors: Tung Chien Hung, 董建宏
• Other Authors: Hsu Tse Shan
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/45121588590925445918

碩士 === 逢甲大學 === 土木及水利工程研究所 === 88 === It is time consuming to perform a traditional consolidation test. For the shake of saving time, the traditional logarithm of time fitting method has been modified by the author''s advisor. Such a modified scheme has the following three advantages. These are: (1) With the add of a computer graphic program, the position for 100% degree of consolidation can be predicted during a consolidation test; (2) Based on zero excess pore water pressure, the range of the primary consolidation is separated clearly from that of the secondary compression; (3) Influence of the secondary compression is eliminated within a consolidation test. Thus, the modified logarithm of time fitting method has great potential to be used in the near future. To prove the usefulness of the above-mentioned method, special consolidation tests for three different types of soils were conducted. Results from this research indicate that (1) The modified logarithm of time fitting method is better than the traditional one; (2) The theoretical value of degree of consolidation, corresponding to the inflection point of a consolidation curve, is to be 60%. Such a value is different from that (about 45%) of a real test result; (3) According to the results of this research, the predicted location for 100% degree of consolidation can be improved; (4) Besides the stiffness of the measuring system, the content of dissolved air in water was proved to be a serious factor for causing low measured excess pore water pressure during the initial stage of a consolidation test.