高压旋喷桩承载特性变化规律现场试验研究

基于现场物理试验测量高压旋喷桩桩身沉降量以及桩周摩擦阻力，获得其随顶部荷载以及桩深变化的基本规律，进而总结高压旋喷桩承载特性的变化规律。结果表明，在桩体发生破坏之前，高压旋喷桩的沉降量随顶部荷载增大呈线性递增；当小荷载时，摩擦阻力随桩顶载荷的增大而增大，但并非一直呈线性变化，在达到一定沉降量后其增加很小；摩擦阻力从桩身下部开始逐渐向上发展，并随荷载的增大而增加；随着上部结构荷载的增大，进入塑性区后的高压旋喷桩复合地基的沉降呈现非线性。

Study on the Rule of Changes in Bearing Characteristic of High Pressure Jet Grouting Pile Base on Field Test

For high pressure jet grouting piles, field tests are designed and carried out by measuring the pile settlement and the frictional resistance around pile to obtain their basic change rules with different loads on pile top and different pile depths, and the rule of changes in bearing characteristic of high pressure jet grouting pile. The results show that the settlement distribution of high pressure jet grouting pile increases linearly along with increase in load on pile top, before destruction. With a small load, the frictional resistance increases together with the increase in pile top load, hut not always in a linear mode. The increase is very small when the settlement reaches to a certain extent. With increasing load, the frictional resistance of a pile comes into play first in the lower part of the pile and then develop to the upper part. With increasing load on the upper structure, the settlement of jet grouting pile composite foundation presents a nonlinear change when it enters into plastic zone.