摘要
常规桩基、复合桩基和刚性桩复合地基中桩-筏连接形式的不同和桩身的垂直度对桩身内力有显著影响,现有规范和计算方法对此仅作定性描述,没有定量分析,给设计和计算带来困难。文章通过具体算例,针对同一工况,分别按照常规桩基、复合桩基和刚性桩复合地基进行设计,基于"m"法计算出上述3种情况下的桩身应力并进行了对比,同时按规范允许偏差范围,计算了垂直度对桩身内力的影响。结果表明,如仅考虑水平荷载,常规桩基和复合桩基在桩顶1/4范围内产生较大弯矩,而刚性桩复合地基中的桩身内力则远小于前两者,如考虑桩身在规范允许的垂直度范围,刚性桩复合地基中的桩身内力迅速增大,数值接近常规桩基和复合桩基。建议在桩身1/4范围内应加强配筋,刚性桩复合地基在该范围内不宜选用素混凝土桩,该范围外的其它部位可适当降低要求。
The different pile-raft connection forms of ordinary pile foundation, composite pile founfation, rigid pile composite foundation and the vertical degree of the pile body have a great influence on the internal force of pile. The existing specifications and the calculation method only make the description of determining the nature, without quantitative analysis and given the difficulties to the design and calculation. The paper analyses the effect of different connection forms of pile-raft on pile stress under the same condition, respective designed by ordinary pile foundation, composite pile foundation, rigid pile composite foundation and obtain each form of pile stress by m method. Also calculating the influence of the vertical degree according to the allowable deviation of the existing specifications. The result showed that, if only the horizontal load in considered, the ordinary pile foundation and composite pile founfation have a large moment on the one quarter of the pile top and the rigid pile composite foundation is far less than the two former. If the allowable deviation of the existing specifications are in considered, the pile stress of rigid pile composite foundation have increased a lot and close to the two former in numerical. The rage of the one quarter of the pile top should strength the reinforcement, the plain concrete pile in refuse in the rigid pile composite foundation, the other place can decrease requirement.
出处
《江苏建筑》
2015年第5期74-77,共4页
Jiangsu Construction
基金
国家自然科学青年基金(51008159)
国家自然科学基金面上项目(51278244)
关键词
连接形式
桩身应力
垂直度
复合地基
复合桩基
connection form
pile stress
vertical degree
composite ground
composite pile foundation
