置换深度估算的一维波动方程法

基金项目:

华东地质学院博士基金资助项目 2000Y2JJ007

One-Dimensional Wave Equation Model for Estimating Replacement Depth of Dynamic Replacement

1.
Department of Resources and Env ironmental Engineering, East China Geological Institute, Fuz hou 344000, China
2.
Department of Civil Engineering, Zhejiang University, Hangzhou 310027, China

摘要: 强夯置换的应用已逐渐广泛, 但其设计是高度经验性的.强夯置换的理论研究较为肤浅, 特别是置换深度的计算尚无较好的方法.为此, 提出了模拟夯击过程的一维波动方程理论模型; 初步建议了模型中有关参数的取值并用工程实例进行了验证; 用所提出的模型探讨了置换体形成与扩展的基本规律; 给出了应用的简化形式.结果表明, 一维波动方程法及其简化形式与实际吻合较好, 可应用于强夯置换的置换深度估算.
- 强夯置换 /
- 置换深度 /
- 一维波动方程 /
- 参数 /
- 简化公式
Abstract: Dynamic replacement has gained wide application, but its design is highly empirical. There is no way to estimate properly the displacement depth. In this event, this paper draws its attention on this subject, proposes a one dimensional wave equation model and its solution method for the replacement depth estimation, and gives the values of the parameters in this model for reference. Case studies showed this model is satisfactory. Thereafter, the replacement process has been simulated and a simplified formula for the replacement depth estimation is presented.
- dynamic replacement /
- replacement depth /
- one dimensional wave model /
- parameter /
- simplified formula

图 1 第j时段第i单元的受力

Fig. 1. Forces acting on element i at time section j

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图 2 置换深度、夯击击数、单击贯入度关系及其与实测结果比较(实例序号同表 1)

Fig. 2. The relationships between displaced depth and number of blows, penetration depth of per blow and comparison with measured results

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图 3 不同条件对H_r的影响

a.H_r-WH关系; b.W与H组合对H_r的影响; c.土质对H_r的影响

Fig. 3. Effect of different conditions on replacement depth

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图 4 简化公式的计算结果及其与实测值的比较

Fig. 4. The calculated results using simplified formula and comparison with measured results

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表 1 国内几个强夯置换工程概况

Table 1. Outlines of some projects in China treated by dynamic replacement

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