高海拔剧烈干湿循环在役排土场安全状态评价

doi:10.16265/j.cnki.issn1003-3033.2023.10.2246

摘要/Abstract

摘要：

为揭示剧烈干湿循环作用对高海拔地区石灰石排土场边坡安全状态的影响,针对高海拔矿区水泥用石灰岩矿区1号、2号在役石灰石排土场边坡,基于非饱和-饱和渗流理论,引入非饱和土抗剪强度方程、基质吸力分布规律方程,开展数值计算,研究剧烈干湿循环下非饱和-饱和渗流场的演化特征并对排土场边坡进行安全状态评价。研究结果表明:在干湿循环作用下,石灰石排土场边坡表层土体由非饱和状态向饱和状态转变;随干湿循环次数增加,石灰石排土场边坡最大竖向位移持续增加,数值计算边坡最大累积竖向位移值与实际监测值较为吻合;石灰石排土场边坡安全系数随干湿循环次数增加而持续衰减;石灰石在役排土场边坡在剧烈干湿循环作用下处于稳定状态。

关键词: 高海拔, 剧烈干湿循环, 排土场, 安全状态, 边坡

Abstract:

In order to reveal the effects of severe drying-wetting cycles on the limestone dump slopes safety status at high altitudes. The slopes of No.1 and No.2 in-service dump in limestone mining areas for cement in high-altitude mining areas was taken as the research object. The unsaturated soil shear strength equation and the matrix suction distribution equation were imported based on the unsaturated-saturated seepage theory. Therefore, the evolution characteristics of the unsaturated-saturated seepage field in the dump slopes under severe drying-wetting cycles were analyzed by numerical calculation, and the safety state of the limestone dump slope was evaluated. The results show that under the action of drying-wetting cycles, the soil changed from the unsaturated to the saturated state on the limestone dump slope. With the increasing number of drying-wetting cycles, the maximum vertical displacement of the limestone dump slope continues to increase. The numerical calculations of the maximum vertical displacement of the slope are in good agreement with the actual monitored values. What is more, as the number of drying-wetting cycles increases, the factor of safety of the limestone dump slope continues to decrease. In addition, it was found that the limestone dump slope in-service is stable under the action of severe drying-wetting cycles.

Key words: high altitude, severe drying-wetting cycle, dump, safety state, slope

董建军, 姜浩, 闫斌, 杨嫡. 高海拔剧烈干湿循环在役排土场安全状态评价[J]. 中国安全科学学报, 2023, 33(10): 94-103.

DONG Jianjun, JIANG Hao, YAN Bin, YANG Di. Evaluation of safety state for dump in-service under severe drying-wetting cycles at high altitude[J]. China Safety Science Journal, 2023, 33(10): 94-103.

图/表 22

图1

图2

图3

表1

SWCC模型基本参数

β/(kPa^-1)	k/(m·s^-1)	$γ w$ /(kN·m^-3)	m
0.005	2.5×10^-6	9.8	0.15

表1

表2

图4

图5

图6

图7

图8

图9

图10

图11

图12

图13

表3

图14

图15

图16

表4

表5

表6

参考文献 10

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工程材料	天然容重/ (kN·m^-3)	饱和容重/ (kN·m^-3)	内摩擦角/(°)	黏聚力/ kPa
碾压堆石坝	20.5	—	35	5
人工填土	21.5	22.5	25.3	4
松散碎石土	20.5	21.0	20	8
稍密碎石土	21.0	22.0	22	10
强风化花岗闪长岩	22.5	22.8	30	40
中风化花岗闪长岩	25.2	25.5	38	500
碾压废石	20.4	—	35	—

干湿循环次数	主影像	从影像	时间基线/ d	空间基线/ m	入射角/ (°)
1	2021-05-28	2021-06-09	12	-13.656	42.110
2	2021-07-03	2021-07-15	12	-6.516	42.123
3	2021-08-20	2021-09-01	12	-42.573	42.120
4	2021-09-01	2021-09-13	12	-44.365	42.113

干湿循环次数	1号排土场边坡			2号排土场边坡
干湿循环次数	模拟值/ mm	监测值/ mm	相对误差/%	模拟值/ mm	监测值/ mm	相对误差/ %
1	5.3	4.7	12.8	6.2	5.3	17.0
2	10.8	10.1	6.9	12.7	11.4	11.4
3	17	15.9	6.9	19.5	17.8	9.6
4	23.4	22	6.4	26.6	24.3	9.5

工况	二等排土场边坡安全稳定性标准	南排土场边坡安全稳定性标准
自然	1.20~1.25	1.25
降雨	≥1.10	1.15

干湿循环次数	安全系数			稳定性
干湿循环次数	1号排土场	2号排土场	安全稳定性标准	1号排土场	2号排土场
1	1.453	1.352	>1.15	稳定	稳定
2	1.385	1.305	>1.15	稳定	稳定
3	1.329	1.242	>1.15	稳定	稳定
4	1.288	1.195	>1.15	稳定	稳定