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通过对3根端后注浆大直径超长灌注桩的现场试验,采用双循环法进行加载,采用沉降杆法测试工程桩顶、桩底的沉降,同时通过应力计测试桩身不同断面的轴力。为研究软土地区大直径超长灌注桩提供有价值的数据。试验表明:桩底沉降较小,最大加载时约为3mm,试桩顶的累计沉降几乎全部由桩身压缩量产生;桩端后注浆处理后,由于桩底沉降较小,桩身桩土相对位移减小,使桩侧土层摩阻力相对于不考虑后注浆时有明显提高,提高比例约为40%~50%,桩端阻力约占总承载力的24%。
Through the field test of three end-grouting long-diameter large-diameter cast-in-place bored piles, the double-loop method was used to load the pile. The method of settlement rod method was used to test the settlement of the top and bottom of engineering pile. At the same time, force. It provides valuable data for studying large diameter overlength bored piles in soft soil area. The tests show that the settlement of pile bottom is small, and the maximum settlement is about 3mm. The cumulative settlement of test pile top is almost totally caused by the amount of pile compression. After grouting, the settlement of pile bottom is small, The relative displacement decreases so that the friction resistance of the soil layer on pile side is obviously improved compared with that of the latter grouting. The increase ratio is about 40% ~ 50% and the pile end resistance is about 24% of the total bearing capacity.