钢管桩负摩阻力及水平位移的测定

本文介绍了一种新仪器--瑞士生产的滑动测微计及其在测定桩中负摩阻力的应用。目前该仪器正用于我国东部海滨某电厂地基钢管桩负摩阻力及水平位移的测定。八个月的观测表明该仪器特别适用于各类岩土工程的长期观测。在4.6m高的堆载条件下,实测最大轴向力约800kN,虽继续增长,但每月约增长30kN,三年后其极限值将接近按有效应力公式计算的值;堆载区边缘钢管桩中的弯曲应力已超过容许应力,水平位移已达600多毫米。本文还对观测结果与土体沉降、地表水平位移及孔隙水压力资料进行了对比分析。

Determination of Negative Friction and Horizontal Displacement for Steel Pipe Piles

This paper presents a new instrument, Sliding-Micrometer-ISETH, and its application to determination of negative friction of piles. This instrument is now used to determine negative friction and horizontal displacement of steel pipe piles for a huge power station in East of China. Eight month’s measurements demonstrate that this instrument is specially suitable for long-term measurement of variety of geotechnical engineering. In the case of stack load with a high of 4.6m, the measured maximum axial load is about 800 KN with the rising rate of 30 KN per month, whose critical value will be lower than that calculated according to effective stresses and approximate to that, if additional pore pressure is considered. The bending stress is higher than allowable stress, and the horizontal displacement is over 600 mm in a pile located at boundary of stack area. A comparison analysis is made for measured results with the data of ground settlement, horizontal displacement and pore pressure.