岩溶地区管桩复合地基单桩承载特性试验研究

Experimental Study on the Bearing Characteristics of Single Pile in Pipe Pile Composite Foundation in Karst Areas

随着城市化进程的发展,城市用地到了寸土必争的地步,因此原先不适合大型工程的岩溶地区也被频频开发。以岩溶地区复合地基中的管桩静载试验为载体,开展了基本分布式光纤传感技术的应变测试,测试管桩承载力的分布情况,分析探讨了管桩在各级荷载下的力学参数及变形情况。试验揭示了管桩在静载试验中的变形规律,并由此间接得出桩身的轴力,侧摩阻力分布。结果表明,施加的荷载在一定的大小范围内越大,桩身应变、应力、轴力和累计变形越大;桩身应变、轴力总体上有沿着桩身逐渐减小的趋势,桩端处的应变和轴力最小。

With the development of urbanisation,urban land has come to the point where every inch of it is in demand,and as a result,karst areas,which were previously unsuitable for large-scale projects,are frequently developed.In this paper,strain tests with basic distributed fibre optic sensing technology were carried out to test the distribution of the bearing characteristics of tubular piles in composite foundations in karst areas,and the mechanical parameters and deformation of tubular piles under various levels of loading were analysed and discussed.The tests revealed the deformation pattern of the tubular pile in the static loading test,and the axial force and lateral frictional resistance distribution of the pile was indirectly derived from this.The results showed that the greater the applied load within a certain size range,the greater the strain,stress,axial force and cumulative deformation of the pile;the strain and axial force of the pile generally tended to decrease gradually along the pile body,with the smallest strain and axial force at the end of the pile.