Improvement Of Liquefaction Discrimination Method Based On Surveys Of The Standard Penetration Test Data In Chinese Code

The soil liquefaction is one of the typical earthquake disaster, is also aglobal scientific issues. For soil liquefaction research has been nearly fivedecades of history, in which the discriminating approach of liquefaction is thefirst step of earthquake-proof and seismic design in engineering. Thediscriminating approach not only determines the safety of the structure butalso the cost of the project. So the reliability of discriminating approach hasbecome a very important issue. The development of reasonable and reliablemethod to protect the safety of China’s national economy is of greatsignificance.The liquefaction discriminating methods use SPT as basic indicators areincluded in the China’s construction specifications. The basic framework ofthese specifications and composition data are derived from the1970s and1980s, even to this day, the relationship between the various methods is alsounclear. However, earthquake both in China and abroad in recent years, havehappened the liquefaction phenomenon. This provided an opportunity to testand improve the existing liquefaction distinguishing method.This paper collected the SPT data of liquefaction site, these data from thetypical earthquake both in China and abroad. By analyzing the sources andcharacteristics of these SPT data, we can learn the difference and contactbetween various methods, and can also meet the shortage of the existingmethods, then put forward a new discriminating model. Test the model by realdata, to provide support for the amendments to the specification liquefactionmethod of our country.The main objects and fruits of this paper are:1. Summarizing the China mainland liquefied survey record, analysis thesources and constitute of the SPT data. Have an in-depth understanding of thedata, which used to form the “Code of Seismic Design of Building”.2. Analyzing with the liquefaction survey data of Japan’s Kobeearthquake in1995and1999Chi-Chi earthquake in Taiwan, and comparingwith the previous liquefaction data in mainland China, to furtherunderstanding of the compositional characteristics of the domestic andinternational SPT liquefied survey data.3. The paper reviews and summarizes the development and evolution ofthe liquefaction evaluation method based on SPT in “Code of Seismic Designof Building” of China, and it also analyses the results of metohds adopted inbuilding codes of different versions using liquefication survey data inmainland China, thus showing the reliability and feasibility of the currentcode.4. Using the survey data in mainland China, the paper compares the liquefaction evaluation methods including Seed simplified method and theSPT-based method used in six codes from mainland China. It analyses theinitial conditions of these methods, and test the discriminant formula usingrefinements of subdividing intensity, so as to master the reliability andfeasibility of the discrimination methods both at home and abroad.5. To presenting a new discrimination model to attack the disadvantageof existent method, and use survey data of the liquefaction site such asmainland China, Chi-chi and Kobe earthquake. Comparing with the variety ofmethods in different conditions, then evaluate the feasibility and reliability ofthe new hyperbolic model.