中文摘要：

港珠澳大桥岛隧结合段管节下部基础采用降水堆载预压＋高压旋喷桩的复合地基形式。常见的原位测试技术不能合理评价地基加固效果,基于半无限空间的布辛涅斯克解,设计了一种采用堆载方式模拟地基应力分布用以分析评价管节沉降的试验方法,通过预先埋置的高精度静力水准系统实测加载过程中的地基沉降,获得较好试验数据。用分层总和法、考虑变形模量非线性的切线模量法与实测数据及数值计算结果对比分析,结果表明切线模量法与实测值更为接近。试验表明以堆载方式模拟实际附加压力进而研究复合地基沉降变形特性的方法直接有效,可作为重要工程地基评价的辅助手段。研究结果对于高压旋喷桩复合地基的设计计算和现场原位测试具有一定的参考意义。

英文摘要：

Several ground treatment methods were applied in the joint section of the island and the tunnel of Hong Kong-Zhuhai-Macau Bridge（HZMB） to reduce the deformation of the foundation below the tunnel. Part of the ground under the tunnel was treated with the preload and the high pressure jet grouting piles（JGP）. There is more than 10 meters backfilled sand layer over the treated foundation. The current field tests such as the core bowling,the standard penetrate test（SPT） and plate test are not suitable for evaluating the reinforcement effect. A full scale load test based on the Boussinesq theory was designed with the heaped load method to simulate the additional stress distribution of the immersed tube tunnel foundation. The good settlement results were obtained utilizing a serial of pre-embedded high precision hydrostatic levelling systems（HLS）. The tangent modulus method considering the impact of modulus nonlinearity was employed for calculating the nonlinear settlement of the soft ground. The calculated results were compared with the experimental data and the numerical simulation results. The results obtained using the calculation model are quite close to the field measured data.