Seepage and stability analysis of pore air pressure on a high-bench dump under heavy rainfall
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摘要: 強降雨作用下排土場非飽和帶中的孔隙氣壓力會阻礙散土體的雨水入滲，從而進一步影響排土場的安全穩定。然而傳統分析方法往往將孔隙氣壓力視為大氣壓力而忽略其對排土場安全的影響。本文依托江西某礦山高臺階排土場工程，基于現場實驗和調查結果，結合水平分層的排土場典型剖面，分析了傳統方法與考慮孔隙氣壓力的高臺階排土場滲流規律及其安全穩定性，探討了強降雨條件下孔隙氣壓對高臺階排土場濕潤鋒、孔隙水壓力和邊坡安全系數的影響。研究結果表明：降雨入滲初期的孔隙氣壓不顯著，其對高臺階排土場穩定性不產生直接影響；但隨著降雨的持續，孔隙氣壓作用開始顯現，使得高臺階排土場的入滲速率降低，濕潤鋒下移速度變慢，孔隙水壓上升變緩，強降雨對高臺階排土場穩定性的影響也出現一定延時；在降雨入滲中期，孔隙氣壓將保持恒定，延時效應會隨入滲深度的增加而增強；在降雨入滲后期，當濕潤鋒下移至分層臨界面時，孔隙氣壓平衡被破壞，將繼續增大直至新的恒定值，對高臺階排土場的影響加劇；在濕潤鋒下移至相同深度時，孔隙氣壓作用下的高臺階排土場安全系數明顯降低。研究成果將為強降雨條件下的高臺階排土場的長期安全運行和災害監測預警提供理論依據。Abstract: Under heavy rainfall, the pore air pressure in the unsaturated zone of a dump hinders rainwater infiltration in loose soil, which further affects the safety and stability of the dump. However, traditional analysis methods often regard pore air pressure as atmospheric pressure and ignore its impact on dump safety. Relying on the high bench dump project of a copper mine in Jiangxi, basing on the field test and survey results and combing with the horizontal slice of a typical dump profile, the seepage law and safety stability of a high bench dump with traditional methods while considering the pore air pressure were analyzed. Moreover, the influence of pore air pressure on a wet front, pore water pressure, and slope safety factors of high bench dump under heavy rainfall conditions were discussed. The research results show that pore air pressure at the initial stage of rainfall infiltration is not significant, and pore air pressure does not have a direct impact on the stability of the high bench dump. However, as the rainfall continues, the effect of the pore air pressure begins to appear, reducing the infiltration rate of the high bench dump. Further, the downward movement speed of the wetting front becomes slower, the pore water pressure rises slowly, and the influence of the heavy rainfall delays the stability of the high bench dump. In the middle of rainfall infiltration, the pore air pressure remains constant, the delay effect varies, and the penetration depth increases. In the late stage of rainfall infiltration, when the wetting front moves down to the critical plane of the layering, the pore air pressure balance is destroyed, continuing to increase to a new constant value, which increases the impact on the high bench dump. When the traditional method of wetting front and considering the pore air pressure of wetting front move down to the same depth, the safety factor of the high bench dump under the action of pore air pressure is obviously reduced. The research results provide a theoretical basis for long-term safe operation and disaster monitoring and early warning of high bench dump under heavy rainfall conditions.
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Key words:
- high bench dump /
- heavy rainfall /
- wetting front /
- pore air (water) pressure /
- slope stability
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圖 1 降雨條件下排土場邊坡受力分析圖（不考慮孔隙氣壓）
Figure 1. Force analysis of the dump under rainfall conditions (without considering the pore air pressure)
圖 2 降雨條件下排土場邊坡受力分析圖（考慮孔隙氣壓）
Figure 2. Force analysis of the dump under rainfall conditions (considering the pore air pressure)
圖 3 粒徑隨排土場堆積高度變化規律。（a）顆粒尺寸≥100 mm；（b）0.1 mm<顆粒尺寸<100 mm
Figure 3. Diameter changes with the dump height: (a) particles size ≥ 100 mm; (b) 0.1 mm < particles size < 100 mm
圖 10 強降雨條件下不同時段孔隙水壓力分布情況
Figure 10. Distribution of pore water pressure indifferent periods
表 1 高臺階排土場滲透系數計算結果
Table 1. Permeability coefficient of the high dump
Testing position Permeability coefficient/(cm·s?1) Step 239 m 3.51 × 10?3 Step 223 m 3.49 × 10?3 Top of the step 200 m 2.50 × 10?3 Middle of the step 200 m 4.70 × 10?3 Bottom of the step 200 m 5.00 × 10?3 
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表 2 高臺階排土場巖土力學參數
Table 2. Mechanical parameters of the high dump
Rock–soil layer Natural unit weight, γ/(kN·m?3) Saturated unit weight, γs/(kN·m?3) Water-bearing condition Cohesion, C/kPa Internal friction angle, Φ/(o) Permeability coefficient, k/(m·s?1) Unclassified waste rock 19.20 20.50 Saturated 42.4 30.3 3.50 × 10?3 Natural 63.0 35.6 Top of the packing material 18.60 19.70 Saturated 31.7 27.8 2.50 × 10?3 Natural 55.0 33.0 Middle of the packing material 19.40 20.70 Saturated 39.0 27.0 4.70 × 10?3 Natural 65.0 36.0 Bottom of the packing material 19.80 21.00 Saturated 44.7 32.3 5.00 × 10?3 Natural 68.0 37.2 Weathered layer 20.00 21.50 Saturated 55.0 31.7 5.20 × 10?7 Bedrock 23.50 24.50 Natural 350.0 40.0 1.20 × 10?8
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表 3 降雨工況設計
Table 3. Design of the rainfall condition
Rainfall
conditionRainfall intensity/
(mm·d?1)Duration/
hTotal precipitation/
mmRainstorm 311.7 6 77.925 12 155.850 18 233.775 24 311.700 30 389.625
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表 4 高臺階排土場安全系數計算結果
Table 4. Safety factor of the high dump
Profile Duration of rainfall/h Safety factor Influence degree of pore air pressure/% Without considering pore air pressure Considering pore air pressure 1-1 profile 0 1.815 1.815 0 3 1.638 1.656 1.06 6 1.545 1.600 3.44 12 1.426 1.486 4.01 18 1.364 1.425 4.26 24 1.343 1.377 2.45 30 1.339 1.355 1.20 2-2 profile 0 1.789 1.789 0 3 1.581 1.597 1.00 6 1.464 1.525 3.98 12 1.309 1.384 5.42 18 1.253 1.302 4.76 24 1.210 1.245 2.81 30 1.194 1.218 1.98
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參考文獻
[1] Zheng K H, Luo Z Q, Luo C Y, et al. Layered gravel soil slope stability of a waste dump considering long-term hard rain. Chin J Eng, 2016, 38(9): 1204鄭開歡, 羅周全, 羅成彥, 等. 持續暴雨作用下排土場層狀碎石土邊坡穩定性. 工程科學學報, 2016, 38(9):1204 [2] Su Y H, Li C C. Slope stability analysis based on Green-Ampt infiltration model under intermittent heavy rainfall. J Hunan Univ (Nat Sci) , 2020, 47(3): 28蘇永華, 李誠誠. 間歇性強降雨下基于Green-Ampt入滲模型的邊坡穩定性分析. 湖南大學學報(自然科學版), 2020, 47(3):28 [3] Wang G J, Tian S, Hu B, et al. An experimental study on tailings deposition characteristics and variation of tailings dam saturation line. Geomech Eng, 2020, 23(1): 85 [4] Wang S H, He J, Yang T J. Numerical Analysis on stability of slope considering rainfall infiltration. J Northeast Univ (Nat Sci) , 2018, 39(8): 1196 doi: 10.12068/j.issn.1005-3026.2018.08.026王述紅, 何堅, 楊天嬌. 考慮降雨入滲的邊坡穩定性數值分析. 東北大學學報(自然科學版), 2018, 39(8):1196 doi: 10.12068/j.issn.1005-3026.2018.08.026 [5] Hu Q G, Yuan N, Liu D S, et al. Analysis of rainfall infiltration process and stability of soil slop with multilayer structure. China J Highw Transp, 2018, 31(2): 67 doi: 10.3969/j.issn.1001-7372.2018.02.007胡慶國, 袁寧, 劉登生, 等. 多層結構土質邊坡降雨入滲過程及穩定性影響分析. 中國公路學報, 2018, 31(2):67 doi: 10.3969/j.issn.1001-7372.2018.02.007 [6] Kong Y F, Song E X, Yang J, et al. Rainfall’s effect on the stability of unsaturated slopes. J Civil Architect Environ Eng, 2013, 35(6): 16孔郁斐, 宋二祥, 楊軍, 等. 降雨入滲對非飽和土邊坡穩定性的影響. 土木建筑與環境工程, 2013, 35(6):16 [7] Wang L. Research on the Key Technique of Stability and Safety Control of the Large Dump in Open-Pit Mine[Dissertation]. Beijing: University of Science and Technology Beijing, 2015王莉. 露天礦大型排土場穩定性及安全控制關鍵技術研究[學位論文]. 北京: 北京科技大學, 2015 [8] Huang G H. Stability analysis of waste dump with complex terrain under heavy rainfall infiltration. Chin J Geotech Eng, 2013, 35(Suppl 2): 292黃剛海. 強降雨入滲下復雜地形排土場穩定性分析. 巖土工程學報, 2013, 35(增刊2): 292 [9] Wang G J, Gao Y W, Tang Y J. Research on the mechanism for chemical clogging and its effect on the stability of tailing dam. Bulgarian Chemical Communications, 2017, 49(1): 228 [10] Morel-Seytoux H J. Infiltration affected by air, seal, crust, ice and various sources of heterogeneity//Proceedings of ASAE National Conference on Advances in Infiltration. Chicago, 1983: 132 [11] Grismer M E, Orang M N, Clausnitzer V, et al. Effects of air compression and counterflow on infiltration into soils. J Irrigat Drainage Eng, 1994, 120(4): 775 doi: 10.1061/(ASCE)0733-9437(1994)120:4(775) [12] Weir G J, Kissling W M. The influence of airflow on the vertical infiltration of water into soil. Water Resour Res, 1992, 28(10): 2765 doi: 10.1029/92WR00803 [13] Latifi H, Prasad S N, Helweg O J. Air entrapment and water infiltration in two-layered soil column. J Irrigat Drainage Eng, 1994, 120(5): 871 doi: 10.1061/(ASCE)0733-9437(1994)120:5(871) [14] Hammecker C, Antonino A C D, Maeght J L, et al. Experimental and numerical study of water flow in soil under irrigation in Northern Senegal: Evidence of air entrapment. Eur J Soil Sci, 2003, 54(3): 491 doi: 10.1046/j.1365-2389.2003.00482.x [15] Sun D M, Zhu Y M, Zhang M J. Study on numerical model for water–air two-phase flow in unsaturated soil. Chin J Geotech Eng, 2007, 29(4): 560 doi: 10.3321/j.issn:1000-4548.2007.04.015孫冬梅, 朱岳明, 張明進. 非飽和帶水–氣二相流數值模擬研究. 巖土工程學報, 2007, 29(4):560 doi: 10.3321/j.issn:1000-4548.2007.04.015 [16] Sun D M, Zhu Y M, Zhang M J, et al. Analysis of rainfall infiltration process considering influence of pore air pressure. Rock Soil Mech, 2008, 29(9): 2307 doi: 10.3969/j.issn.1000-7598.2008.09.001孫冬梅, 朱岳明, 張明進, 等. 考慮氣相影響的降雨入滲過程分析研究. 巖土力學, 2008, 29(9):2307 doi: 10.3969/j.issn.1000-7598.2008.09.001 [17] Sun D M, Feng P, Zhang M J. Refined analysis of stability of unsaturated soil slope due to rainfall infiltration considering the effect of gas phase. J Tianjin Univ, 2009, 42(9): 777孫冬梅, 馮平, 張明進. 考慮氣相作用的降雨入滲對非飽和土坡穩定性的影響. 天津大學學報, 2009, 42(9):777 [18] Li Y N, Lv H X, Lin X C. Regularities of air pressure changes in soil infiltration. Acta Univ Agric Boreali-occidentalis, 1995, 23(6): 72李援農, 呂宏興, 林性粹. 土壤入滲過程中空氣壓力變化規律的研究. 西北農業大學學報, 1995, 23(6):72 [19] Li Y N, Liu S B. Changes of two soil phases in the process of infiltration. J Northwest Sci-tech Univ Agric Forest (Nat Sci Ed) , 2002, 30(6): 177李援農, 劉書榜. 土壤入滲氣液兩相流的變化過程. 西北農林科技大學學報(自然科學版), 2002, 30(6):177 [20] Li Y N, Fei L J. Green-Ampt model for unsaturated infiltration affected by air pressure entrapped in soil. J Hydraul Eng, 2005, 36(6): 733 doi: 10.3321/j.issn:0559-9350.2005.06.016李援農, 費良軍. 土壤空氣壓力影響下的非飽和入滲格林-安姆特模型. 水利學報, 2005, 36(6):733 doi: 10.3321/j.issn:0559-9350.2005.06.016 [21] Wang Z, Feyen J, Nielsen D R, et al. Two-phase flow infiltration equations accounting for air entrapment effects. Water Resour Res, 1997, 33(12): 2759 doi: 10.1029/97WR01708 [22] Han T C, Ma S G, Xu R Q. Research on delayed effect of landslides caused by air pressure under heavy rainfall. Rock Soil Mech, 2013, 34(5): 1360韓同春, 馬世國, 徐日慶. 強降雨條件下氣壓對滑坡延時效應研究. 巖土力學, 2013, 34(5):1360 [23] Regmi R K, Lee G, Jung K. Analysis on failure of slope and landslide dam. KSCE J Civil Eng, 2013, 17(5): 1166 doi: 10.1007/s12205-013-0049-y [24] Wang J C, Yu J L, Gong X N, et al. Research on effect of closed air pressure on slope stability under intense rainfall. Rock Soil Mech, 2014, 35(11): 3157王繼成, 俞建霖, 龔曉南, 等. 大降雨條件下氣壓力對邊坡穩定的影響研究. 巖土力學, 2014, 35(11):3157 [25] Zhang X Y, Zhu Y M, Fang C H. The role fore air flow in soil slope stability analysis. J Hydrodyn Ser B, 2009, 21(5): 640 doi: 10.1016/S1001-6058(08)60195-X [26] He J. The Moisture Response and Landslide Stability Analysis Under the Condition of Rainfall Infiltration [Dissertation]. Beijing: China University of Geosciences (Beijing), 2018何健. 降雨入滲條件下的水氣響應及邊坡穩定性分析[學位論文]. 北京: 中國地質大學(北京), 2018 [27] Ai X T, Wang G J, Zhang C, et al. Research on the stability of high dump with wide graded waste rock. Rock Soil Mechanics, 2020, 41(11): 3777艾嘯韜, 王光進, 張超, 等. 寬級配廢石的高排土場穩定性研究. 巖土力學, 2020, 41(11):3777 [28] Wang G J, Kong X Y, Yang C H. Research on the representation of granular vertical size grading and numerical simulation method with the typical waste rock site. Teh Vjesn, 2015, 22(3): 677 doi: 10.17559/TV-20150428103311 [29] Cao Y H, Li Y. Test verification and modification of Mohr-Coulomb criterion. J Cent South Univ (Sci Technol) , 2020, 51(2): 399 doi: 10.11817/j.issn.1672-7207.2020.02.014曹藝輝, 李鈾. Mohr-Coulomb準則的試驗驗證與修正. 中南大學學報(自然科學版), 2020, 51(2):399 doi: 10.11817/j.issn.1672-7207.2020.02.014 [30] Wang G J, Yang C H, Zhang C, et al. Research on particle size grading and slope stability analysis of super-high dumping site. Rock Soil Mech, 2011, 32(3): 905 doi: 10.3969/j.issn.1000-7598.2011.03.044王光進, 楊春和, 張超, 等. 超高排土場的粒徑分級及其邊坡穩定性分析研究. 巖土力學, 2011, 32(3):905 doi: 10.3969/j.issn.1000-7598.2011.03.044 [31] Han L, Shu J S, Shang T, et al. Experiment study on the physical and mechanical parameters of soft rock remolding in waste dump. J Min Saf Eng, 2019, 36(4): 820韓流, 舒繼森, 尚濤, 等. 排土場散體軟巖重塑物理力學參數研究. 采礦與安全工程學報, 2019, 36(4):820 [32] Wang G J, Tian S, Hu B, et al. Evolution pattern of tailings flow from dam failure and the buffering effect of debris blocking dams. Water, 2019, 11(11): 2388 doi: 10.3390/w11112388 [33] Li Y, Yang Y S, Mao Q S, et al. Researches on general stability for dump slope based on three-dimensional geologic model. Rock Soil Mech, 2013, 34(Suppl 1): 533李躍, 楊永生, 毛權生, 等. 基于三維地質模型的排土場邊坡整體穩定性探究. 巖土力學, 2013, 34(增刊1): 533 [34] Ai X T, Wang G J, Kong X Y, et al. The scale effect of coarse-grained materials by triaxial test simulation. Adva Civil Eng, 2021, 2021: 6665531 [35] Deng D P, Li L, Zhao L H. Limit equilibrium method(LEM) of slope stability and calculation of comprehensive factor of safety with double strength-reduction technique. J Mountain Sci, 2017, 14(11): 2311 doi: 10.1007/s11629-017-4537-2 [36] Tao Z G, Li H X, Cai H, et al. Test on the slope stability of full-section high dump under rainfall. J China Coal Soc, 2020, 45(11): 3793陶志剛, 李華鑫, 曹輝, 等. 降雨條件下全段高排土場邊坡穩定性模型實驗研究. 煤炭學報, 2020, 45(11):3793 [37] Wang G J, Kang J W, Du C, et al. Study on tailings dam over-topping failure model test and break mechanism under the rainfall condition. Teh Vjesn, 2017, 24(6): 1897 -
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