軟土地基堤圍穩定性計算方法

賈愷; 楊光華; 湯連生; 李澤源

doi:10.13374/j.issn2095-9389.2019.05.003

軟土地基堤圍穩定性計算方法

doi: 10.13374/j.issn2095-9389.2019.05.003

賈愷^{1, 2, 3},
楊光華^{1, 2, 4, ,},
湯連生³,
李澤源⁴

1.
廣東省水利水電科學研究院, 廣州 510610
2.
廣東省巖土工程技術研究中心, 廣州 510610
3.
中山大學地球科學與工程學院, 廣州 510275
4.
華南理工大學, 廣州 510641

基金項目:

國家自然科學基金資助項目 51778152

廣東省省級科技計劃資助項目 2014B070706008

廣東省水利科技創新資助項目 2015-09

詳細信息

通訊作者:
楊光華，E-mail: yghsks@21cn.com

中圖分類號: TG142.71
計量
- 文章訪問數: 1110
- HTML全文瀏覽量: 480
- PDF下載量: 24
- 被引次數: 0
出版歷程
- 收稿日期: 2018-07-19
- 刊出日期: 2019-05-01

Calculation method of stability of soft soil foundation embankment

JIA Kai^{1, 2, 3},
YANG Guang-hua^{1, 2, 4
, ,},
TANG Lian-sheng³,
LI Ze-yuan⁴

1.
Guangdong Research Institute of Water Resources and Hydropower, Guangzhou 510610, China
2.
Geotechnical Engineering Technology Center of Guangdong, Guangzhou 510610, China
3.
School of Earth Sciences and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
4.
South ChinaUniversity of Technology, Guangzhou 510641, China

More Information

Corresponding author: YANG Guang-hua, E-mail: yghsks@21cn.com

摘要

摘要: 在軟土地基上采用整體穩定分析方法確定的安全系數可能會存在偏大的危險, 當堤身強度高于堤基軟土的強度過多時, 可能存在堤基軟土失穩的安全系數小于整體穩定安全系數的情況, 因此, 對于軟土地基的堤圍穩定計算, 除進行整體穩定計算外, 還應復核堤基軟土的穩定性.并通過案例證明了該觀點的正確性, 同時提出了軟土堤基穩定計算的方法, 并以該方法為基礎, 提出了堤腳受沖刷情況下的整體穩定性計算方法.可為軟土地基的堤圍安全提供更合理安全的設計計算方法.
- 軟土地基 /
- 堤防 /
- 圍堰 /
- 極限平衡法 /
- 地基承載力
Abstract: Strengthening the embankments on soft foundations is generally capable of improving stability. Based on this understanding, for soil foundations whose stability does not meet specification requirements, embankments are strengthened during design to improve the overall stability of the foundation. However, the actual increase is limited. In particular, for soft foundations, increase in the strength of the embankment is high will damage the foundation. Thus, the use of high-strength geotextiles is common in this situation. This study considers that the safety factor, which is usually determined using the overall stability analysis method, may feature a high level of risk. When the strength of the embankment differs considerably from the strength of the soft foundation, the safety factor of soft foundation embankment may be less than the overall stability safety factor. Therefore, to calculate the stability of soft soil foundation embankment, in addition to the overall stability calculation, the stability of the soft foundation should be reviewed. This study illustrates the correctness of this point of view. A method for calculating the stability of soft foundation is proposed. Based on this method, a calculation method for the overall stability of the embankment under scouring condition is proposed. Based on the original foundation bearing capacity model, the method considers the difference between the dike foundation and rigid foundation. Variable elasticity width fully reflects the most likely point of foundation failure occurrence when the dike is damaged. The stability of the foundation is increased by increasing the accuracy of the slip zone. Based on this method, this study also discusses the stability of the foundation under the scouring of the embankment. This method can provide a more reasonable and reliable design calculation for the safety of embankments on soft foundations.
- soft soil foundation /
- embankment /
- cofferdam /
- limit equilibrium method /
- foundation bearing capacity

HTML全文

圖 1 地基承載力計算示意圖

Figure 1. Calculation of foundation bearing capacity

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圖 2 地基破壞形式圖. (a) 滑裂面破壞; (b) 有壓密核破壞

Figure 2. Foundation damage form: (a) slip failure; (b) compacted core failure

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圖 3 三角形荷載局部被動土壓力示意圖

Figure 3. Part of triangular load passive earth pressure

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圖 4 三角形荷載整體被動土壓力分布圖

Figure 4. Triangular load passive earth pressure

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圖 5 b>b₀時地基承載力計算示意圖

Figure 5. b>b₀ foundation bearing capacity

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圖 6 式(8)和式(12)同工況對比圖

Figure 6. Comparison of formulas (8) and (12) under the same working condition

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圖 7 H-b關系圖

Figure 7. Relation between H and b

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圖 8 極限平衡法計算示意圖

Figure 8. Calculation of limit equilibrium method

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圖 9 最大應變增量圖

Figure 9. Maximum strain increment

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圖 10 由位移矢量連線確定滑弧

Figure 10. Determination of the arc by the displacement vector

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圖 11 由最大法向位移梯度確定滑弧

Figure 11. Determined of the arc by the maximum normal displacement

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圖 12 工況1各方法計算結果匯總圖

Figure 12. Results of each method in Condition 1

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圖 13 工況2各方法計算結果匯總圖

Figure 13. Results of each calculation in Condition 2

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圖 14 安全系數K與抗剪強度τ/τ₀關系

Figure 14. Relation between safety coefficient K and shear strength τ/τ₀

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圖 15 堤腳沖刷示意圖

Figure 15. Scouring of the embankment

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圖 16 廣州南沙區某水閘外江側圍堰剖面圖(標高單位：m，其余單位：mm)

Figure 16. Sectional view of the cofferdam near the sea of a sluice in Nansha District, Guangzhou(elevation unit: m, other unit: mm)

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表 1 各驗算工況填土參數表

Table 1. Parameters of filling

工況	堤身強度參數		堤基強度參數
工況	c/kPa	φ/(°)	c/kPa	φ/(°)
工況1	10	20	4	3
工況2	60(加筋后等效)	30(加筋后等效)	4	3

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表 2 工況1各方法抗滑穩定安全系數匯總表

Table 2. Anti-slip stability factor of each method

計算方法	安全系數	差值比/%
瑞典條分法	0.839	12
簡化Bishop法	0.838	12
強度折減法(Flac)	0.750	—
地基承載力法	0.720	4

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表 3 工況2各方法抗滑穩定安全系數匯總表

Table 3. Stability and safety coefficients of each method

計算方法	安全系數	差值比/%
瑞典條分法	1.242	63
簡化Bishop法	1.140	50
強度折減法(Flac)	0.760	—
地基承載力法	0.720	5

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表 4 反算參數后各方法計算結果對比表

Table 4. Comparison of the results of each method

工況	計算方法	安全系數	差值比/%
工況1	瑞典條分法	1.008	6
	簡化Bishop法	1.038	9
	強度折減法(Flac)	0.950	—
	地基承載力法	0.800	16
工況2	瑞典條分法	1.528	58
	簡化Bishop法	1.425	47
	強度折減法(Flac)	0.970	—
	地基承載力法	0.800	18

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表 5 不同堆填材料對整體穩定的影響對比表

Table 5. Comparison of the effects of different landfills on the overall stability

c/kPa	φ/(°)	安全系數
c/kPa	φ/(°)	瑞典條分法	簡化Bishop法	強度折減法
5	4	0.815	0.843	0.870
8	8	0.931	0.975	0.920
10	10	0.986	1.026	0.940
15	15	1.099	1.116	0.960
25	18	1.267	1.228	0.970
60	30	1.676	1.413	0.970

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表 6 反算參數后各方法計算結果對比表

Table 6. Comparison of the results of each method

坡率，1∶m	極限高度/m	2.5 m堆填時的安全系數
原狀	1.8	0.72
1∶5	1.6	0.64
1∶4	1.6	0.64
1∶3	1.5	0.60
1∶2	1.5	0.60
1∶1.5	1.4	0.56
1∶1	1.3	0.52

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表 7 南沙區某圍堰抗滑穩定各方法計算對比表

Table 7. Results of each working condition of the cofferdam

工況	計算方法	安全系數
填至3 m高程 (圍堰高度6 m)	簡化Bishop法	1.318
填至2.2 m高程 (圍堰高度5.2 m)	簡化Bishop法	1.554
	強度折減法	0.770
	地基承載力法	0.770

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參考文獻(14)

[1]	Shen Z J. Limit analysis of soft ground reinforced by geosynthetics. Chin J Geotech Eng, 1998, 20(4): 82 http://www.ixueshu.com/document/3bc3f55247d6eed69a06415266ca81be318947a18e7f9386.html
[2]	Sun D Y, Bao C G, Ding L Q. Some assumptions on the design of embankment DAMS in China's soft base. Water Resour Hydropower Eng, 2007, 38(2): 54 https://www.cnki.com.cn/Article/CJFDTOTAL-SJWJ200702014.htm 孫東亞, 包承綱, 丁留謙. 對我國軟基上加筋堤壩設計規范的一些設想. 水利水電技術, 2007, 38(2): 54 https://www.cnki.com.cn/Article/CJFDTOTAL-SJWJ200702014.htm
[3]	Li G X. Some problems in design of geosynthetic-reinforced soil structures. Chin J Geotech Eng, 2013, 35(4): 605 https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201304003.htm 李廣信. 關于土工合成材料加筋設計的若干問題. 巖土工程學報, 2013, 35(4): 605 https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201304003.htm
[4]	Xu G M, Gao C S, Zhang L, et al. Preliminary study of stability of levee on soft ground. Chin J Rock Mech Eng, 2005, 24(13): 2315 doi: 10.3321/j.issn:1000-6915.2005.13.020 徐光明, 高長勝, 張凌, 等. 軟土地基上堤防穩定性研究. 巖石力學與工程學報, 2005, 24(13): 2315 doi: 10.3321/j.issn:1000-6915.2005.13.020
[5]	Zhu B, Feng L Y, Chai N B, et al. Centrifugal model test and numerical analysis of deformation and stability of seawall on soft clay. Rock Soil Mech, 2016, 37(11): 3317 https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201611034.htm 朱斌, 馮凌云, 柴能斌, 等. 軟土地基上海堤變形與失穩的離心模型試驗與數值分析. 巖土力學, 2016, 37(11): 3317 https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201611034.htm
[6]	Chen S L, Zhang B Y, Zhang J M, et al. Centrifugal modeling of reinforced embankments on soft clay. Chin J Rock Mech Eng, 2005, 24(15): 2751 doi: 10.3321/j.issn:1000-6915.2005.15.026 陳勝立, 張丙印, 張建民, 等. 軟基上加筋防波堤的離心模型試驗. 巖石力學與工程學報, 2005, 24(15): 2751 doi: 10.3321/j.issn:1000-6915.2005.15.026
[7]	Li H Q, Ge D L, Pan L H. Centrifugal model test of deepwater breakwater on soft soil foundation. Port Waterway Eng, 2018(3): 14 doi: 10.3969/j.issn.1002-4972.2018.03.003 李賀青, 葛棟林, 潘良鵠. 深水防波堤軟土地基離心模型試驗. 水運工程, 2018(3): 14 doi: 10.3969/j.issn.1002-4972.2018.03.003
[8]	Lei G H, Zhang H M, Liu F X, et al. Plasticity limit analysis of stability of embankment fill on layered soft soil ground. Chin J Geotech Eng, 2018, 40(8): 1522 https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201808022.htm 雷國輝, 張惠敏, 劉芳雪, 等. 成層軟土地基上土堤填筑穩定性的塑性極限分析. 巖土工程學報, 2018, 40(8): 1522 https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201808022.htm
[9]	Huang J W, Chen X P, Chen H, et al. Failure mechanism and engineering countermeasures of coastal levee on soft soil foundation of Guangdong Province. Chin J Rock Mech Eng, 2006, 25(Suppl 2): 3393 https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2006S2007.htm 黃井武, 陳曉平, 陳華, 等. 廣東沿海軟基堤壩破壞機制及工程對策. 巖石力學與工程學報, 2006, 25(增刊2): 3393 https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2006S2007.htm
[10]	Liu C H, Xiao Z Y, Wang J H, et al. Finite element analysis of road embankment on soft soil reinforced with geotextiles. Rock Soil Mech, 2004, 25(Suppl 2): 325 https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2004S201U.htm 劉春虹, 肖朝昀, 王建華, 等. 土工織物加固軟土路堤的有限元分析. 巖土力學, 2004, 25(增刊2): 325 https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX2004S201U.htm
[11]	Li K F, Xie X Y, Zhang J F, et al. Failure behavior analysis of embankment built on soft subgrade. Rock Soil Mech, 2009, 30(7): 2075 doi: 10.3969/j.issn.1000-7598.2009.07.035 劉開富, 謝新宇, 張繼發, 等. 軟土地基上路堤填筑的破壞性狀分析. 巖土力學, 2009, 30(7): 2075 doi: 10.3969/j.issn.1000-7598.2009.07.035
[12]	Yu G D. Experimental Studies on Large Sandbag Cofferdam Stability in deep soft soil[Dissertation]. Guangzhou: South China University of Technology, 2015 于桂東. 深厚軟基大砂袋圍堰穩定性試驗研究[學位論文]. 廣州: 華南理工大學, 2015
[13]	Yang G H. Calculation of strength of soft soil under complex loads such as embankments and dikes// 3rd National Conference in Foundation Treatment. Qinhuangdao, 1992: 622 楊光華. 路堤及堤壩等復雜荷載下軟土地基的強度計算//第三屆全國地基處理學術討論會論文集. 秦皇島, 1992: 622
[14]	Lu P Y, Xu Z H. Calculation of foundation strength and deformation // Lu Peiyan's Scientific Works and Papers. 2006: 1 陸培炎, 徐振華. 地基強度與變形的計算// 陸培炎科技著作及論文選集. 2006: 1