The mechanism and some new work laws of negative skin friction along the single pile or wharf bent piles is analyzed . the engineering construction measure decreased the negative skin friction is presented . an improved empirical formula has been put forward for the calculation of the negative skin friction 研究得出港口码头桩基、排架桩基受到负摩擦力作用时的工作机理、发现新的规律，发现桩负摩擦力的性状和有利的工程施工措施，并提出港口单桩、排架桩基负摩擦力的计算方法。
At last , the paper solves the depreciation problems of the vessel that is sealed up for keeping and port and dock , bringing forward that the parts that are still worn down during the sealed period should be depreciated and the parts having no or less spoilage should not be depreciated according to the theory of parts measurement . the port and dock , able to be wholly renewed through locally overhauling in turn , should apply the method of replacement accounting to process accountancy . xin dawang ( finance and accounting ) directed by professor : shao ruiqing 上海海运学院jn ：学位论义最后论述了封存船舶和港口码头的折旧问题，本文提出：在部件计价基础上，船舶封存应只对封存时仍继续损耗的部件计提折旧，其余未使用或者损耗很小的部件则不计提折旧：港口码头可以通过局部轮番大修实现整体更新，每个泊位根据大修制度定期进行大修，等到所有泊位都经过大修以后，则整个码头都同新建的码头泊位发挥的效用相同，进而应运用重置会计对码头固定资产进行会计核算，以正确处理港口码头的修理支出以及折旧计提问题。
