【正文】 the energy of waves with large wave heights is large which leads to larger impulsive pressure acting on deck than that of small waves. For the situation with the same wave heights, which means the wave dynamics are identical , the largest impulsive pressure is dependent on the clearance and the wave steepness. For large clearance cases, the peak pressure usually appears at a large wave steepness, whereas the peak pressure is linked to a small wave steepness at a small clearance situation. Fig. 5. Dimensionless maximum uplift force versus the relative clearance.3. 2. 1. 2 Effect of deck widthUplift forces on deck are presented in Fig. 6 for the maximum uplift loads ( with exceedance probability 1% ) plotted against the deck width B. The forces tend to increase as the deck width increases, then the increase slows down and the forces remain constant after the deck width increases to a certain value. In some cases the forces show a slight decrease. Based on tests, the trends of forces can be explained as follows: for narrow deck the width of which is smaller than the wave acting width, the whole deck is exposed to the wave attack and the wider the deck, the larger the wave acting surface and further the larger the total forces. The forces keep invariable when the deck width is equivalent to the wave acting width. As deck bees wider then, the force decreases with the increment of deck width. It indicates that the deck is subjected to the action both of the crest and the trough and the bined effect result in reduction of the total force. Assuming the deck width is larger than one time wave length, it can be expected that the total forces will increase in respect that the deck experience two waves action. From the above analysis, it seems that the distribution length is related to the wave acting width, so taking into account of wave length to denote the pressure distribution length is unreasonable. Fig. 6. Maximum uplift load versus the width of deck.A clear dependence of dimensionless uplift forces on Ls/ B is illustrated in Fig. 7. The trends of dimensionless force with the posite variable Ls/ B show that the force tends to decrease as the relative deck width increases ( namely the ratio of Ls/ B decreases) , then the decrease slows down when the deck width exceeds or is beneath a certain value. It attributes to the following mechanics: first, as the deck width is much smaller than the width of wave acting surface, the action concentrates on the contact region, the pressure distribution on the deck are almost constant, thus the slight variation of the deck width has little influence on the total force. Second, with the deck width increasing in the limit of not more than the wave acting width, the slightly nonhomogeneous of wave action is responsible to the decrease of the dimensionless total forces. Third, as the deck width is in excess of the wave acting width, the total forces increase little and the pressure distribution length remains unchanged , therefore the dimensionless forces seem almost constant. It should be noted that, at a large clearance level, the deck width is mostly larger than the wave acting width, and thus the dimensionless uplift forces slightly decrease with the increasing deck width.3. 2. 2 ?? Prediction Model of Uplift LoadsThe dominant influence factors for the loading process on the deck of the exposed highpile jetty were found to be the impact angle of wave surface, air layer and the wave dynamics. Based on the analysis of measured data, new prediction method was developed by utilizing the envelope for all tests in order to make sure of safety in engineering application, as shown in Eq. ( 3) . The effect of the relative width of deck is included and the coefficient 1. 1 is introduced in calculating the crest elevation to represent the wave reflection from the deck and the downstanding beams. Fig. 7. Dimensionless maximum uplift load versus Ls / B.3. 2. 3 ?? Comparison of the Measured Dimensionless Uplift Force with the Prediction by New MethodPredictions of waveindeck uplift loads by Eq. ( 3) are pared with the measured data in Fig. 8 and Fig. 9. The parison shows that the new prediction method gives a good result on uplift forces with large magnitude, while 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 not the critical situation for design. Generally, the model gives conservative results for design.3. 2. 4 ?? Comparison of the New Prediction Method with the Existing Prediction MethodsFour examples of parison between the new prediction model and the existing three prediction models are given in Fig. 10. The distribution lengths of pressure are taken as L s/ 4, x 1% ( without wave reflection coefficient) , L s/ 6, x 1% ( with wave reflection coefficient ) respectively for the Goda model ( 1967) , the existing guidance model ( 1994) , the Guo and Cai model ( 1980) , and the new prediction method. For case that x 1% is larger than B, it is taken as B .The parison shows the following details:As a result without considering the effect of the deck width, the existing guidance model overestimates the forces on the wide deck (with width B = Ls ) , but underestimates the forces on the narrow deck (with width B = L s/ 8) . The existing guidance model predicts that the maximum uplift force appears at the still water level, which disagrees with the trend explored in the test that the peak force occurs at the relative clearance above the still water level ??h/ ??1% = 0. 4~ 0. 8. The force reduces sharply with the clearance increase due to the linear relationship, and thus the predicted uplift force is paratively small in large clearance. The range of clearance corresponding to the effective uplift force is narrow without considering the effect of wave reflection in calculating