饱水粘性土主固结理论(续): 主固结过程粘性土含水量与时间的关系

沈孝宇; 初振环

饱水粘性土主固结理论(续): 主固结过程粘性土含水量与时间的关系

深圳市工勘岩土工程有限公司, 广东深圳 518026

详细信息

作者简介:
沈孝宇(1934-), 男, 教授, 从事岩土工程及土体固结理论研究工作.E-mail: evanmarco-1981@hotmail.com

中图分类号: P642
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出版历程
- 收稿日期: 2008-12-01
- 刊出日期: 2009-09-25

Primary Consolidation Theory of Saturated Soft Clay (Continuation): The Relationship between Clay's Water Content and Time during Primary Consolidation

Shenzhen Gong kan Geotechnical Engineering Co., Ltd., Shenzhen 518026, China

摘要

摘要: 论文的前文(饱水粘性土主固结理论) 已从理论上导出粘性土“主固结比(η) ”、“极限主固结量(S_η) ”及其主固结度U_η的计算方法, 它们取决于粘性土的初始含水量和液限(W_t、W_L) 而与固结应力p无关.作为前文的续篇, 主要是探求一维主固结过程含水量和时间(t) 的变化关系(W_t=f(t, z)).根据一维固结物理模型及假设条件建立的含水量为因变量的主固结二阶偏微分方程并通过特定的边界条件和初始条件, 利用分离变量法和三角函数正交原理解得主固结过程含水量和时间的关系式, 并获得主固结系数Θ及其时间因数Δ的新表达式, 它们在形式上与太沙基固结方程相似, 但实质内容上不一致, 前者是探索粘性土含水量变化, 后者是超静孔压u的变化, 利用新的一维主固结方程进一步导出主固结量(S_t), 平均主固结度(U_t) 及主固结剩余量(ΔS) 等新一组表达式, 利用工程实际数据分别计算表明新的主固结系数Θ所含的相关物理量除含水量外, 其他的物理量如渗透系数(K), 超静孔压水头高度(h₁), 粘性土比重(G_s) 等都不具实质的影响.
- 一维固结 /
- 主固结系数 /
- 主固结时间因素 /
- 超静孔隙水压力
Abstract: The primary consolidation ration, utmost primary consolidation and the calculational methods of primary consolidation degree have been draw in the last paper (Study on the Theory Primary Consolidation of Saturated Soft Clay), they lie on the initial moisture and liquid limit, but they are independent of consolidate stress.Qua continuation, the connection of moisture and time during one dimensional consolidation has been searched.According to the one-dimensional-consolidated model and assumption, the second-order partial differential equations which moisture as the dependent variable has been established according to the one-dimensional-consolidated model and assumption.Through specific boundary conditions and initial conditions, using separation of variables and trigonometric functions orthogonal winner of the consolidation process of understanding the relationship between water content and style.The new formula of coefficient of primary consolidation and time factor has been obtained.They are similar in form with Terzaghi consolidation equation, but they are different in the substance, the former has searched change of the water content of soft clay, but the latter has searched change of excess pore water pressure.The new expressions of primary consolidation, the average degree of consolidation and remainder of primary consolidation have been drawn by the new one-dimensional primary consolidation equation.According to engineering data, it has been indicated that permeability coefficient, excess pore water pressure head, and the proportion of soft clay have not affected the new coefficient of primary consolidation Θ, except moisture.
- one dimensional consolidation /
- coefficient of primary consolidation /
- time factor of primary consolidation /
- overpore water pressure

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图 1 两相土的主固结物理模型

a.软土(两相土) 初始状态(t=0);b.t时间排水后固结状态(t=t₁); 1.固体状态(固体颗粒及结合水); 2.液态水(孔隙中的重力水); 3.排出液态水后减少的孔隙体积

Fig. 1. Physical model of primary consolidation on two-phase soil

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图 2 超静孔隙水压水头高度(h) 与含水量(W) 关系曲线

Fig. 2. Correlation curve of hydraulic head of excess pore water pressure (h) and moisture (W)

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图 3 不同初始含水量(W₁) 状态下粘性土含水量与时间关系曲线

取深港西部通道粘性土的物理性质数据: W_L=50%;γ_s=19kN/m³; h_s=9 m; G_s=2.67;γ_w=10 kN/m³; H=2 m; k=2.868×10^-5 m/d=3.32×10^-8 cm/s

Fig. 3. Correlation curves of moisture of soft clay (W_t) and consolidation time (t) on differentinitial moistures (W₁)

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图 4 不同初始含水量(W₁) 状态下粘性土固结度与时间(t) 关系曲线(粘性土的物理性质参数及计算数据同图 3)

Fig. 4. Correlation curves of degree of consolidation (U_t) of soft clay and consolidation time (t) on different initial moistures (W₁)

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图 5 不同初始含水量(W₁) 状态下粘性土主固结量(S_t) 与时间(t) 关系曲线(粘性土的物理性质参数及计算数据同图 3)

Fig. 5. Correlation curves of primary consolidation (S_t) and consolidation time (t) on different initial moistures (W₁)

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表 1 超静孔压(h₁) 不变条件下, 渗透系数(K) 与主固结系数(Θ) 的关系

Table 1. Relationship between the permeability coefficient and coefficient of consolidation in unchanged excess pore water pressures conditions

表 2 渗透系数K不变条件下超静孔压(h₁) 和主固结系数(Θ) 的关系

Table 2. Relationship between excess pore water pressures and coefficient of consolidation in unchanged permeability coefficient conditions

表 3 渗透系数K和超静孔压(h₁) 都不变条件下粘性土液限含水量W_L和主固结系数的关系

Table 3. Relationship between liquid limit and coefficient of consolidation in unchanged permeability coefficient and excess pore water pressures conditions

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