Yu Run Li

Study on Lateral Dynamic Response of Pile Foundation in Liquefiable Soil by Using FBG Method

The study on lateral dynamic response of pile foundation in liquefiable soil is a significant part about seismic damage. In this paper, a new data acquisition system of FBG and calculation methods is used in the small shaking table test. The results show that FBG method used in this test is proved to be efficient and acceptable in both time characteristics and precision characteristics, it may be widely applied in the future doubtlessly. What’s more, the characteristics of p-y curves in different peak accelerations are discussed. And varying of maximum stress and displacement by corresponding acceleration is discussed. A contrast about p-y curve between dry sand and saturate sand is related, which provides a new direction in research about p-y curve.

The Evolution and Discriminate Analysis of the SPT Discrimination Methods in Code of Seismic Design of Building in China

By collecting the China mainland liquefied survey record, analyzed the constitution of the SPT data. Have an in-depth understanding of the SPT liquefaction discrimination model in the Code of Seismic Design of Building in China. Reviews the development and evolution of the discrimination formula in the seismic code, and analyzed the results of the methods adopted in seismic codes of different versions by liquefaction survey data in mainland China, then discuss the reliability and feasibility of the current code. Eventually provide support for the amendments to the specification liquefaction method of our country.

New Prediction Formula of Sand Liquefied on Bachu-Jiashi Earthquake Survey

Through the Bachu-Jiashi Ms6.8 earthquake liquefaction investigation and test, obtain the 47 the standard penetration test date, examine the existing standard applicability based on standard penetration test of soil liquefaction identification method, and put forward the new sandy soil liquefaction evaluation formula. Analysis shows that the current assessment formula base on SPT counts of soil liquefaction are not applicable to Xinjiang region, will give the risky results. In the new survey data of soil liquefaction evaluation model established of five parameters by the earthquake intensity, the measured SPT counts, datum SPT values, groundwater level, and sand buried depth. The datum SPT values, the influencing coefficients of water and sand depths are gain by a normalized method and by an optimizing method. Establish new formula of soil liquefaction evaluation to the success judging rate is higher, the model shows that constructing reasonable and calculation formula is reliable, can be employed for regional code formulation in Xinjiang area.

In Situ Test Methods in Bachu-Jiashi Earthquake Liquefied Evaluation

The serious soil liquefaction phenomenon in Bachu-Jiashi earthquake on 24th February, 2003, which is the most prominent phenomena of sand liquefaction since the Tangshan Great Earthquake in 1976. Based on the earthquake liquefied investigation, inspect SPT and CPT applicability in situ tests. The results show that our country SPT specification and CPT specification of non-liquefied sites evaluation rate is higher than liquefied sites evaluation success rate, the liquefied sites evaluation rate are 88% and 88% respectively, but for liquefied sites evaluation rate are 38% and 55%. The result is tends to danger and the reason need further investigation, so establish a suitable liquefied prediction method should be to the future work in the local area.

A Study on the Analysis Method of Soil Layer Seismic Response in Seasonal Frozen Site

The analysis of ground motion on seasonal frozen soil mainly focused on the conventional soil, neglecting the impact of the permafrost which causes the obvious defeats in the existed calculation procedure. In this paper, the author proposed that we should apply the field test of shear wave velocity to the soil layer response calculation, improve the test method of dynamic shear modulus, and adopt the regular analysis method of soil layer response to the calculation of frozen soil site.

Research on Zoning Technology of the Liquefaction Seismic Settlement Based on MAPGIS

Liquefaction seismic settlement is one of the typical nature disasters caused by earthquake, which always leads to wall cracking due to uneven settlement of the building. In the previous research work, scientists only study on the failure mechanism and the calculation method of the seismic settlement, the zoning technology about liquefaction seismic settlement have not been proposed. So that, utilizing the function of MAPGIS, this paper puts forward the zoning technology of the liquefaction seismic settlement.

A New Method for Dynamic p-y Curves of Pile-Cap Structure in Layered Soil

Lateral dynamic response of pile foundation in liquefiable soil has been one of the focal problems of the geotechnical engineering field and varieties of test methods are put forward by experts and scholars. In the dissertation, a shaking table test is based on and a new calculation method is involved too. It’s the first time that using Fiber Prague Grating (FBG) technology in the method of study on lateral dynamic response of pile foundation in liquefiable soil. Experimental results indicate that calculation by method of FBG is more accurate than that by acceleration integral method. Data processing shows that p-y curve of pile foundation in liquefiable soil can be better to indicate the actual dynamic constitutive relation, and it establishes the theoretical basis of experimental study and engineer application of pile foundation in liquefiable soil

Study on In Situ Test Based on Survey of Bachu Earthquake

Based on survey of the Bachu-Jiashi earthquake liquefaction sites, much new basic liquefaction information were obtained and China’s liquefaction database was enriched. A detailed investigation of the Bachu earthquake liquefaction site was conducted, in which three kinds of in situ test measures were used to obtain the site information, and given China mainland SPT data of liquefaction site increase by 40%. By site investigation, international standard liquefaction site CPT data were obtained, and also, the first measurement of liquefaction site data by SPT and CPT index was conducted. With the new data, the feasibility of liquefaction discrimination methods of China was inspected.

Research on Regional Dividing Technology for Liquefaction-Induced Lateral Spreads Based on MAPGIS

A simplified empirical statistical regression method for liquefaction-induced lateral spreads is stated in this paper. It is used to determine the corresponding calculation parameters for Tangshan city and its south region where 36 borehole data were collected. Using two multiple linear regression formulas, the free face model and the ground slope model are developed to calculate the lateral spread at each filed survey point in the region. The liquefaction-induced lateral spreads map was divided into hazard zones according to the calculated horizontal displacement at each borehole based on MAPGIS.

Feasibility of Vs Liquefication Evaluation Methods by Bachu Xinjiang Earthquake Data

A discrimination model for soil liquefaction is established by analyzing the liquefied and non-liquefied sites in the Bachu Xinjiang earthquake, based on 44 shear wave velocity data. One of them is based on the Code for seismic design of buildings, which is a linear model. The model is brief and convenient, while the evaluation success rate is 80%. But compared with the nonlinear model, the linear model is not advanced enough. The other model is based on probability analysis, and the evaluation success rate can reach up to 93%. And the discrimination results are high in reliability rely on real data analysis.