Research on evaluation of sedimentation and consolidation properties of clay using RI-density log for dredging and reclamation

在挖泥土上进行了一系列沉降柱试验。并连续进行恒应变固结柱试验。在这些试验中，同时进行了ri密度测井，并测量了ρ_t的深度剖面。在此基础上，对不同含水率粘土进行了弯折单元试验和微型叶片剪切试验。根据试验结果，首先对ri密度测井的可行性进行了探讨。然后求出f-log σ_v‘、w/w_L- logg和w/w_L-log s_u的关系式，其中f为比容，σ_v’为有效应力，w为含水量，w_L为液限，G为弹性剪切模量，s_u为抗剪强度。最后，将密度测井应用于封闭水体和填海造地的野外调查，讨论了密度测井在调查中的适用性。主要结论如下：1。ri密度测井在室内试验中的可行性令人满意。在清水、悬浮液、流体泥浆和底泥（底泥）的每种状态下，均可分别测量出高精度的密度。通过密度和孔隙水压力的测量，可以得到F-log σ_v关系。在w/w_L【近似等于】1.5范围内，可以用一条直线来近似表示这一关系，直线的倾斜度几乎等于标准实验室试验得到的压缩指数C_c的倾斜度。w/w_L- logg关系可以近似为w/w_L【近似等于】1.5内的一条直线。然而，倾角的值与C_c.4不同。w/w_L- logs_u关系可以用w/w_L【近似等于】1.5内的一条直线来近似。那么，倾角的值几乎等于C_c.5的值。验证了ri密度测井在野外调查中的适用性。此外，还提出了一种预测填海土地沉降曲线的简便方法。

A series of settling column tests was carried out on a dredged clay. And continuously, constant rate of strain consolidation column tests were also conducted. During those tests, RI-density log was carried out simultaneously and in-depth profiles of ρ_t were measured. And then bender element tests and miniature vane shear tests were carried out for the clay with a wide range of water content. Based on test results, firstly, feasibility of RI-density log was investigated. Then, relations of f-log σ_v', w/w_L-logG and w/w_L-log s_u were evaluated, where f is specific volume, σ_v' is effective stress, w is water content, w_L is liquid limit, G is elastic shear modulus and s_u is shear strength. And finally, RI-density log was applied to field investigations in closed water body and reclaimed ground, and the adequateness of RI-density log for the investigations were discussed. Main conclusions are as follows.1. The feasibility of RI-density log in laboratory test is satisfactory. In each state of clear water, suspension, fluid mud, and bed mud (bottom sediment), the density can be measured with high accuracy, respectively.2. f-log σ_v' relation can be obtained by measurements of density and pore water pressure. The relation can be approximated by a straight line within w/w_L【approximately equal】1.5, and the value of the inclination of the line is almost equal to that of compression index C_c obtained from the standard laboratory test.3. w/w_L-logG relation can be approximated by a straight line within w/w_L【approximately equal】1.5. However, the value of the inclination differs from that of C_c.4. w/w_L-log s_u relation can be approximated by a straight line within w/w_L【approximately equal】1.5. Then, the value of the inclination is almost equal to that of C_c.5. The adequateness of RI-density log for field investigation is verified. Furthermore, a simple method to predict settlement curve of reclaimed ground was newly proposed.