摘要
介绍了一种能测量沉桩在土中产生的径向应力增量的模型桩试验及其结果，分析了某工程现场实测的孔隙水压力资料，两者均证实了用圆柱孔扩张理论解释单桩周围饱和软土中应力状态变化的适用性．分析表明，在用圆柱孔扩张理论公式估算打桩应力时宜采用常规三轴试验曲线的初始切线模量Ｅｉ计算土的刚度比，并建议用土的上覆有效压力σ′υ代替周围压力σ３计算Ｅｉ值．
A kind of model-pile test capable of measuring radial stress in saturated clay by driving a single pile and its results are described,and in situ data on pore pressure collected on a worksite are analysed.Both the test and the data obtained have proved the applicability of analysing a change in stress condition in saturated clay around a single pile by means of theory of expansion.It is pointed out that in evaluating the stress produced by driving with theory of expansion,initial tangent modulus E i from conventional triaxial test curve can be adopted to calculate rigidity ratio of the soil,and in determing E i,the substitution of an effective overburden pressure σ v for all round pressure σ 3 is proper.
关键词
沉桩
土应力
圆柱孔扩张
刚度比
single pile
soil stress,expansion of pore pressure
rigidity ratio
