深大基础地基回弹再压缩变形计算方法及工程应用

对于深、大基础来说,建筑物完成后基底以下土体往往处于补偿或超补偿状态,此时再压缩沉降变形在建筑物最终沉降变形中占有较大比例,基坑开挖回弹变形及再压缩变形计算应引起重视。回弹比率、再加荷比、再压缩比率等概念的提出及其在回弹变形与再压缩变形研究中的应用,为回弹变形与再压缩变形之间建立了更为清晰、利于计算的关系。土体再压缩变形发展过程中的两阶段线性关系在再压缩变形计算方法中的应用,可对任一再加荷工况下土体再压缩变形进行计算。通过工程实测与计算对比分析可知,该方法的计算结果,对建筑物沉降发展过程的变形控制具有实用性。

Method for recompression deformation of large and deep foundation and its engineering application

For large and deep foundation, the soils under the foundation base are in a state of compensation or overcompensation when the buildings are completed. The recompression deformation accounts for a large proportion in the final settlement. More attention should be paid to the calculation of rebound deformation and recompression deformation. The concepts of rebound proportion, reloading ratio, recompression ratio are proposed and applied in the analysis of the rebound deformation and recompression deformation. A relationship between the rebound deformation and the recompression deformation which is clearer and easy to calculation is created. The two-phase linear law of the recompression deformation is applied in the method for calculating the recompression deformation. So the recompression deformation under each reloading condition can be computed. Through engineering tests and calculation analysis, the results of the proposed method has better engineering practicability for the deformation control of projects.