【正文】 the wave contact length and the crest elevation. The Goda model gives highly large prediction for uplift load, as Goda model is fitted for the open trestle bridge in deepwater, the wave reflection from structure is large and the resulted slamming of interference standing wave is responsible to the great impact pressure on deck.The Guo and Cai model estimates the uplift loads by the impulsive pressure, thus it gives relatively large result. The distribution length Ls / 6 is adopted and proportional to wave length, but is independent of the clearance, which leads to overestimation of wave force with large wave length and for deck with high clearance. Compared with the predictions by other models in Fig. 10, the equations derived here show significant improvement, with consideration of the effect of deck configuration and the effect of wave reflection. Moreover, it should be noted that the forces on downstanding beams and berthing members contribute to large forces on the superstructure of jetty at high clearance level, though in that situation the wave can not reach the deck and the force on deck is zero. Therefore, for large clearance cases, the forces on deck, downstanding beams and berthing members should be calculated separately, and the sum is then the desired result. Applications in case study confirm that it provides a more consistent predict ion with the practical results. Fig. 8. Dimensionless maximum uplift loads and the envelope of the maximum.Fig. 9. Comparison of the measured dimensionless uplift forces with the proposed new prediction method.Fig. 10. Comparison of new prediction model with existing prediction models.3. 3 ?? Probability Distribution of Uplift LoadsWaveindeck uplift load induced by irregular waves is random. The parameterization of the data is in normal distribution, threeparameter Gamma distribution, Weibull distribution and Rayleigh distribution. The KolmogorovSmirnov test is advocated to test the acceptance of the given four models. Conclusion from the study is that it seems to accept the Weibull distribution for 75% of test data sets, mainly those poorly fitted sets are relevant to large clearance case. Deviation at higher clearance is understandable, because for higher level deck, small waves in a random wave sequence can not reach the deck and the values in the corresponding force data set are zero. This results in poor fitting of the Weibull model to measured uplift loads. The analyzed results of the real data confirm that the load distribution obeys Weibull distribution and the conversion ratios of wave loads with different exceedance probabilities are suggested in Table 1.Table 1 Conversion ratio between wave loads with different exceedance probabilities4. ConclusionsA Weibull distribution is proposed to describe the statistical distribution of uplift loads. The conversion ratio of wave loads with different exceedance probabilities is deduced from the measured force analyses, as shown in Table 1.The spatial pressure distribution associated with uplift forces is classified into the impulsive type and the uniform type. The maximum uplift loads generally lag behind the maximum impulsive pressure and are associated with the uniformly distributed pressure. It means that the uplift force related to the maximum impulsive pressure is not the largest . For the uniform distribution, the corresponding pressure is relatively small, while the distribution length is large and increases with the wave length increase and the clearance decrease. Generalization and analysis of the experimental data confirm that the distribution length of the uniform type is equivalent to x 1%. When x 1% is larger than the width of deck B , it is taken as B.The dominant variables for the loading process are the incident wave height, the incident wave length, the clearance of the deck above the still water level, and the deck width. It is shown that the dimensionless uplift load increases to a maximum with the increasing clearance and then decreases. The relative clearance corresponding to the peak force is linked to a range from 0. 4 to 0. 8. When the clearance exceeds the vertical distance that the wave crest could reach the deck, the force bees zero. The trends of dimensionless force with the relative width of deck show that the force tends to decrease as the deck width increases, and then the decrease slows down after the deck width increases or decreases to a certain value.A new predict ion method is developed by using the envelope for all tests and taking into account two main factors, namely the relative clearance and the relative deck width. It shows that the new prediction method gives a conservative result on the uplift force and overall slightly overestimates the load. The uplift load deviations in this model are mostly for the forces with small magnitude. The main trend is that it underestimates the forces at high clearance cases, the corresponding forces are small and it is not the critical situation for design.ReferencesGoda, Y. , 1967. Wave forces on structures, Summer Seminar on Hydraulics , JSCE , B34. ( in Japanese)GUO Da and CAI Baohua, 1980. Calculation of uplift forces of waves on plates for hollow trussed structures, Journal of East China Water Resources University , ( 1) : 14~ 33. ( in Chinese)LI Yanbao and HUANG Lingyan, 1997. Experimental study on uplift forces on superstructure of exposed jetty, Harbor Engineering, ( 6) : 9~ 13. ( in Chinese)Patarapanich, M. , 1984. Forces and moment on a horizontal plate due to wave scattering, Coast. Eng. , 8( 3) : 279~301.REN Bing , LI Xue lin and WANG Y。 d is water depth.Clear trend of the dimensionless uplift load with the relative clearance can be seen in Fig. 5. It shows that the force increases to the maximum with the increasing clearance and then decreases. It should be noted that the relative clearance corresponding to the pe