深基坑土钉墙支护结构设计及工程实例

Structure design and application of the soil-nailed wall in deep foundation pit engineering

深基坑土钉墙支护结构是近年来发展起来的一种新型的挡土技术,由于其经济可靠而且施工快速简便,已经在许多国家得到迅速的发展和应用。尽管目前国内外对土钉墙支护技术的研究已取得了一些可喜的成果,并成功应用于许多的工程实践,但也有少量基坑土钉墙事故发生。特别是现行工程设计中的随意性,或偏于保守,造成浪费,或有盲目性,往往酿成工程事故。文章根据土钉墙支护结构的特点,结合工程实例———北京颐源居Ⅲ期工程现场地质条件,就土钉墙支护结构的土钉长度、间距、土钉倾角及面层等结构参数进行了优化设计。土钉墙强度验算结果表明土钉抗拉断安全系数Ks=2 13>1 5,且抗拔出安全系数Fs=6 44均满足设计要求。其技术经济效益评价也表明该设计方案是可行且经济的。

The soil-nailed wall supporting structure in deep foundation pit is a new supporting technique developing in recent years,and it has been used widely in many countries due to its economics,reliability and quickly & easyly to be constructed. Many delightful productions have been gained these years about the soil-nailed wall supporting technique at home and abroad and it has been applied in many projects successfully, however there are a lot of engineering accidents and engineering practical problems about the technique.Based on the characteristics of soil-nailed wall, taking an example, the parameters of supporting structure such as the length, the space, the inclination and the surface are designed optimized in this paper. The checking results for strength indicate that the designed scheme meet the required standard and the economic appraisal also indicate that the design is feasible and economical.