基于加速度响应的微型桩加固土质边坡效果评价

Evaluation of soil slope reinforced by micro-piles based on acceleration response

为研究地震作用下微型桩加固土质边坡的作用效果,通过大型振动台试验,获得微型桩加固有软弱面的土质坡体桩间土的加速度响应数据,并对试验现象进行串联分析;重点对比在不同地震波加载方向下,桩群不同位置加速度响应的差异,用小波包对采集加速度时域曲线进行分解,分析其频谱特征,并与无软弱结构面的坡体加速度响应一般规律进行对比分析,以此对微型桩支护效果进行定性评价。结果表明:(1)在微型桩加固坡体后,会产生多种释放动能的途径,以保证整个坡体的稳定性。(2)经微型桩加固的测点趋向于无软弱面的均质材料所得到的加速度放大的一般规律,而未加固的山侧测点在滑面上下会产生"加速度错台"现象,表现出未经支护的自然滑坡体的破坏特征。(3)水平向加载时,低频为影响加速度响应的主导频率,而竖直向加载时,除中频段响应小,其余频段均有明显作用。(4)在后排桩河侧滑带上下,高频滤波作用明显,而后排桩山侧频率变化不明显。微型桩加固边坡对整体结构性的提升和边坡的稳定作用显著。

In order to study the effect of micro-pile reinforcement in soil slope under the effect of earthquake action,the acceleration response data of inter-pile soil in soil slope with weak structural surface strengthened by micro-pile is obtained through large-scale shaking table test,and the experimental phenomena are analyzed in series.In the different seismic wave loading directions,analyze the different acceleration response of the pile group at different positions,the acceleration time-history curve is decomposed by the wavelet packet,the spectrum characteristics are analyzed,and compared with the general law of the slope acceleration response of soil slope without the weak structural plane,in this way,the micro-pile support effect is qualitatively evaluated.The results show that:(1)In the micro-pile reinforced slope,a variety of ways to release kinetic energy will be generated to ensure the stability of the entire slope.(2)The acceleration response of measurement point in the micro-pile reinforced slope tends to the general law of acceleration amplification obtained by the homogeneous material without the weak surface,while the unreinforced mountain side measurement point will produce the phenomenon of"acceleration staggered platform"under the sliding surface.Destructive characteristics of unsupported natural landslide bodies.(3)When horizontal loading,the low frequency is the dominant frequency that affects the acceleration response,while in the vertical direction,except for the mid-range response,the other frequency bands have obvious effects.(4)Around the slip zone of the river side of the rear row piles,the high-frequency filtering effect is obvious,while this effect of the mountain side of the rear piled is not obvious.The micro-pile reinforced slope has a significant effect on the overall structural improvement and the stability of the slope.