土压实度的瞬态冲击法测试

为寻找一种无损、快速和准确地检测土压实度的新方法,基于振动能量在土壤中衰减的基本原理,使用重锤冲击压实度不同、含水质量分数不同的土壤,在与冲击点一定距离处的土壤中测取振动响应信号,并对测取的信号在时域和频域上进行分析。试验结果表明:在测试距离一定、含水质量分数相同时,在同一脉冲宽度内振动加速度信号的幅值、有效值均随压实度的增加而增大;在最佳含水质量分数附近的范围内,土壤中含水质量分数对压实度计算结果的影响不大,误差小于1%;在冲击距离为200~400 mm时的测量和计算结果,比较接近真实测量值,距离较近、较远时误差均较大。

Testing on soil's compacting intensity with method of instantaneous hammer blows

Based on the attenuation principle of the vibration in soil,a nondestructive,quick and accurate way of testing soil's compaction is put forward.A serious of hammer blow experiments are conducted on different compactness and water content of soil,and the vibration acceleration are obtained at certain distances.According to time-domain analysis and frequency-domain analysis of the measured experiment data,the results shows that: the amplitude and effective value of vibration acceleration increase with the soil compaction when the distance of measuring points and water content of soil is constant;when water content is near the optimal water content,it has a little influence on the soil compaction,the measuring error is below 1%;the measuring value is closer to the real soil compaction when the distance from measuring point to vibration point is 200~400 mm;but when the distance is longer or shorter than 200~400 mm,the measuring error is bigger.4 tabs,1 fig,13 refs.