黄河口粉质土对振动能量的吸收特征研究  

Study on the Vibration Energy Absorbption Characteristics of the Silt in the Yellow River Estuary

作　　者：马志杰[1] 孟庆生[1] 贾永刚[1] 

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2007年第S1期95-100,共6页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(40172088)资助

摘　　要：在黄河口典型研究区进行冲击荷载实验,在粉土层不同深度处布置检波器、电极及孔压探头,实时监测振前、振中和振后的土体响应。研究黄河口粉质土体对振动能量的吸收特征,并结合土体电性变化、孔压变化等分析其影响因素。研究结果表明:黄河口粉质土体对振动能量的吸收与振动前后土体的状态变化密切相关。振动后,表层土体对振动能量的吸收有所减少,土体电阻率有一定程度的增大,土体的孔隙水压力急剧升高缓慢降低,而且土体的变化响应主要发生在振动初期;黄河口粉质土体的动力响应沿深度方向呈现明显的非均匀性,存在较为明显的动力响应敏感区与相对稳定区。浅层软弱夹层的动力响应尤为明显,能量衰减主要集中在浅层.振动后土体对能量的吸收特征变化和土体的电阻率变化以30～50 cm深度范围的软弱土层最为明显。Impact vibration tests were carried out in a typical area of the Yellow River estuary.Seismic detec- tors,electrodes and pore water pressure probes were laid out at different depths in the silt,and the dynamic re- sponses of the soil were measured during the course of vibration to study the characteristics of vibration energy absorbed by the soil.And their influencing factors were analyzed in combination with the data of electric resis- tivity and pore water pressure of the soil.It is shown that the characteristics of vibration energy absorbed by the soil are closely related to the soil's states of variation before and after the vibration.After vibration,the energy absorbed by the superficial soil decreases slightly,and the electrical resistivity of the soil body increases to some degree,while the pore water pressure in the soil first increases sharply and then decreases slowly;non-unifor- mity of the dynamic responses of the silt in the vertical direction is obviously exhibited.Relatively obvious sensi- tive areas and stable areas in terms of dynamic response can be seen from the analysis,the superficial weak in- terlayer responds more obviously to dynamic loads,and moreover,the decrease of energy mainly concentrates in the superficial layer.After vibration,the energy absorbing characteristics and the electric resistivity variation characteristics of the soil can be observed most obviously at depths between 30～50 cm.

关 键 词：吸收特征 粉土 振动能量 动力响应 

分 类 号：P642.1[天文地球—工程地质学]