考虑有效孔隙率变化的淤泥固化土渗透性研究

doi:10.11988/ckyyb.20231317

长江科学院院报 ›› 2024, Vol. 41 ›› Issue (11): 136-143.DOI: 10.11988/ckyyb.20231317

考虑有效孔隙率变化的淤泥固化土渗透性研究

陶东新¹(), 梧松²(), 刘洪涛¹, 陶敏¹, 王政¹, 詹熠楠¹

¹ 中煤浙江勘测设计有限公司,杭州 310009
² 宁波大学科学技术学院,浙江宁波 315300

收稿日期:2023-11-28 修回日期:2023-12-26 出版日期:2024-11-01 发布日期:2024-11-26
通讯作者: 梧松(1973-),男,广西柳州人,副教授,博士,主要研究方向为地基处理。E-mail:wusong@nbu.edu.cn
作者简介:
陶东新(1973-),男,浙江临海人,正高级工程师,硕士,主要研究方向为地基处理、岩土工程勘察。E-mail:391056119@qq.com
基金资助:
浙江煤炭地质局科技项目(ZMD-2022-02)

Permeability Characteristics of Sludge Solidified Soil Considering the Variation of Effective Porosity

TAO Dong-xin¹(), WU Song²(), LIU Hong-tao¹, TAO Min¹, WANG Zheng¹, ZHAN Yi-nan¹

¹ China Coal Zhejiang Survey & Design Co. Ltd., Hangzhou 310009,China
² College of Science and Technology,Ningbo University, Ningbo 315300,China

Received:2023-11-28 Revised:2023-12-26 Published:2024-11-01 Online:2024-11-26

摘要/Abstract

摘要：

为了解利用自行研制的水玻璃基固化剂制备的淤泥固化土的渗透性,结合扫描电镜试验和压汞试验,分析了土体的微观结构和孔径分布特征随固化剂掺量改变的规律;基于有效孔隙理论建立了一维渗透微分方程,并在此基础上提出一种细粒土的常水头渗透性测试方案,将其应用于固化土的渗透性测试中。通过反压饱和和卸载试验,建立有效孔隙率增量与孔隙水压力的函数关系;利用常水头渗透性测试和数值计算获取土体的渗透性参数。通过测试研究了固化土渗透性参数随固化剂掺量改变的规律。结果表明:随着固化剂掺量增加,固化土颗粒团块结构和孔隙率均呈增大趋势;固化土初始有效孔隙率 $n 0 和$ 起始水力梯度 $i 0$ 单调递减,绝对有效渗透系数 $k$ 先减小再增大,当掺入比为7%时最小。

关键词: 淤泥固化土, 有效孔隙率, 反压饱和, 绝对有效渗透系数

Abstract:

To investigate the permeability of sludge solidified soil prepared using a self-developed water glass-based curing agent, the microstructure and pore size distribution characteristics of the soil were analyzed using scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) with varying amounts of curing agent. Based on the effective porosity theory, a one-dimensional permeation differential equation was established, and a constant head permeability test scheme for fine-grained soil was proposed and applied to the permeability testing of the solidified soil. Through back pressure saturation and unloading tests, the relationship between the effective porosity rate increment and the pore water pressure function was established, and the permeability parameters of the soil were obtained through constant head permeability testing and numerical calculations. The permeability parameters of the solidified soil were studied with varying curing agent content. The results showed that with increasing amounts of curing agent, both the particle structure and porosity rate of the solidified soil increased. The initial effective porosity rate and starting hydraulic gradient of the solidified soil decreased monotonically, while the absolute effective permeability coefficient initially decreased and then increased, reaching a minimum value at a curing agent ratio of 7%.

Key words: sludge solidified soil, effective porosity, backpressure saturation, absolute effective permeability coefficient

中图分类号:

TU411.4土的渗透性试验

陶东新, 梧松, 刘洪涛, 陶敏, 王政, 詹熠楠. 考虑有效孔隙率变化的淤泥固化土渗透性研究[J]. 长江科学院院报, 2024, 41(11): 136-143.

TAO Dong-xin, WU Song, LIU Hong-tao, TAO Min, WANG Zheng, ZHAN Yi-nan. Permeability Characteristics of Sludge Solidified Soil Considering the Variation of Effective Porosity[J]. Journal of Yangtze River Scientific Research Institute, 2024, 41(11): 136-143.

图/表 12

表1 原料土物理性质指标

Table 1 Physical property indicators of raw soil materials

含水量 W/%	天然重度γ/ (kN·m^-3)	孔隙比e	液限 W_L/%	塑限 W_p/%	塑性指数I_p	液性指数I_L
57.9	16.3	1.6	46.8	23.9	22.9	1.3

表2 固化土物理力学性质指标

Table 2 Index of physical and mechanical properties of solidified soil

掺入比/ %	塑限W_L/%	液限W_P/%	塑性指数 I_P	无侧限抗压强度/MPa
0	23.9	46.8	22.9	0
3	27.1	40.9	13.8	0
5	30.3	36.9	6.6	0.212
7	30.2	39.3	9.1	0.310
9	29.6	41.0	11.4	0.255
11	29.4	41.1	11.7	0.240

图1 扫描电镜图像

Fig.1 SEM images

表3 压汞试验数据

Table 3 MIP test data

掺入比/ %	孔隙率/ %	中值孔径/ nm	掺入比/ %	孔隙率/ %	中值孔径/ nm
0	37.22	322.3	7	38.23	395.7
5	38.13	340.4	9	40.70	440.7

图2 孔径-累计进汞量分布曲线

Fig.2 Cumulative intrusion vs. pore sizes

图3 一维渗流连续条件

Fig.3 One-dimensional seepage continuity condition

图4 Δn-p曲线

Fig.4 Δn-p curves

表4 拟合参数C、D取值

Table 4 Fitted values of parameter C and D

掺入比/%	C	D	掺入比/%	C	D
5	0.008 58	0.165 7	9	0.004 07	0.184 9
7	0.007 60	0.167 2

表5 常水头试验测试数据

Table 5 Constant head test data

掺入比/ %	入口压力P₁/ kPa	时间/ s	渗流量Q/ cm³	单位时间渗流量q/ (10^-3 cm³·s^-1)	渗透系数k'/ (10^-6cm·s^-1)
	50	1 371	10.91	7.95	2.12
5	100	1 371	22.97	16.70	2.22
	150	1 371	39.20	28.50	2.53
	50	1 371	7.82	5.70	1.52
7	100	1 371	20.00	14.60	1.94
	150	1 371	34.79	25.40	2.26
	50	1 371	7.33	5.34	1.42
9	100	1 371	21.11	15.40	2.05
	150	1 371	35.93	26.20	2.32

表6 渗透性参数

Table 6 Permeability parameters

掺入比/%	$n 0$	$i 0$	k/(10^-5 cm·s^-1)
5	0.046 8	0.698	2.865
7	0.033 6	0.501	2.227
9	0.031 5	0.469	3.063

表6 渗透性参数

Table 6 Permeability parameters

掺入比/%	$n 0$	$i 0$	k/(10^-5 cm·s^-1)
5	0.046 8	0.698	2.865
7	0.033 6	0.501	2.227
9	0.031 5	0.469	3.063

图5 孔隙水压力和水力梯度分布

Fig.5 Pore water pressure distribution graph and hydraulic gradient distribution graph

表7 变水头试验数据

Table 7 Variable head testing data

掺入比/%	终止水头H₂/cm		渗透量Q/cm³		渗透系数k'/ (10^-7 cm·s^-1)
掺入比/%	试验值	计算值	试验值	计算值	试验值	计算值
5	187.1	187.7	10.15	9.68	4.25	4.04
7	191.8	192.3	6.40	6.01	2.67	2.50
9	191.0	191.5	7.04	6.65	2.94	2.77

考虑有效孔隙率变化的淤泥固化土渗透性研究

Permeability Characteristics of Sludge Solidified Soil Considering the Variation of Effective Porosity

RichHTML

PDF

可视化

摘要/Abstract

引用本文

使用本文

图/表 12

相关文章 0

编辑推荐

Metrics

本文评价