深基坑土钉支护的数值模拟及稳定性分析
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摘要
土钉支护结构是当前比较常用的基坑支护形式之一。它既具有所有支护结构的共性，也有它自身的特性，本文综合了下面四方面内容来模拟土钉支护基坑，通过计算表明因为考虑了多种因素的影响，比较正确地分析了土钉支护机理。
其一，施工力学问题。在结构施工过程中，随着施工进程的变化，结构的形状也在不断的发生变化，与此同时作用在结构上的外载也随之而改变。基坑工程中重要是开挖荷载的计算，本文采用Mana来计算开挖荷载，Mana法是根据有限元法思想，将被挖掉的所有单元高斯点处的应力通过应变矩阵等效到节点上求得，该方法是比较有效的。
其二，主动支护形式。土钉支护法，以尽可能保持、显著提高、最大限度地利用基坑边壁土体固有力学强度，变土体荷载为支护结构体系的一部分。因此说土钉支护为为主动支护形式，这种支护方法具有传统支护形式所无法比拟的优点，值得在更大范围内推广使用。
其三，钉-土相互作用。由于土体与土钉的性质差异大，变形不一致，在二者的接触界面上常产生较大的剪应力，这种剪应力正是土体与土钉之间荷载传递的媒介，正确的研究分析接触面上的受力变形机理，剪切破坏的发展，荷载传递过程，并在计算中加以正确模拟是十分重要的。本文采用界面单元来模拟钉-土之间的相互作用，计算表明该单元能较好地模拟钉-土界面的作用实质。
其四，土钉支护边坡的稳定性验证。土钉支护的边坡需要验证其稳定性，本文采用当前比较流行的强度折减有限元进行了有土钉支护与无土钉支护边坡的稳定性分析，结果比较理想。
The support structure of Soil nailing is one of the support form used in foundation pit. It not only has the common characteristics of foundation pit support form but also has some specialities. In this paper, four aspects of soil nailing were expatiated in detail. Many factors that influence the foundation pit support are considered, and the principle of soil nailing support is analyzed correctly.
(1) Construction mechanics problem The structure shape will be changed along with the construction course. In the course of construction, the external loads will be changed accordingly. Foundation pit engineering is one of the unload problem in the construction mechanics. The computation of excavation load can be regard as the process that the stress of excavation surface is released completely and the excavation surface then changed into the free stress surface. The method of Mana is used to compute the excavation load in this paper. The method of Mana is one of the finite element method, and the method is rather effective.
(2) Active support form The support form of soil nailing can preserve, enhance and impose the soil intension of foundation pit walls. It can change the soil loads into one part of the support construction system. So the soil nailing support can be regard as the initiative support form. The support form has the advantages and can be used widely.
(3)Nailing-soil interaction It is well known that the characteristics of soil is different from the characteristics of soil nailing, and the distortion of them is disagreement. The shearing stress will come into being in the contact surface. The shearing stress is the medium that can transfer the load between soil and soil nailing. It is very important to analyze the principle of deformation, the development of shearing destruct, the process of load transfer and simulate them correctly. In this paper, the interface element is used to simulate the interaction between soil and soil nailing. It is indicated that the interface element can simulate the soil-nailing interface perfectly.
(4) The validation of the slope stability by soil nailing The strength reduction finite element method is used to analyze the stability of the slope timbered by soil nailing and the slope timbered by the traditional support form. It is proved that the stability of the slope timbered by the soil nailing is ideal.
其一，施工力学问题。在结构施工过程中，随着施工进程的变化，结构的形状也在不断的发生变化，与此同时作用在结构上的外载也随之而改变。基坑工程中重要是开挖荷载的计算，本文采用Mana来计算开挖荷载，Mana法是根据有限元法思想，将被挖掉的所有单元高斯点处的应力通过应变矩阵等效到节点上求得，该方法是比较有效的。
其二，主动支护形式。土钉支护法，以尽可能保持、显著提高、最大限度地利用基坑边壁土体固有力学强度，变土体荷载为支护结构体系的一部分。因此说土钉支护为为主动支护形式，这种支护方法具有传统支护形式所无法比拟的优点，值得在更大范围内推广使用。
其三，钉-土相互作用。由于土体与土钉的性质差异大，变形不一致，在二者的接触界面上常产生较大的剪应力，这种剪应力正是土体与土钉之间荷载传递的媒介，正确的研究分析接触面上的受力变形机理，剪切破坏的发展，荷载传递过程，并在计算中加以正确模拟是十分重要的。本文采用界面单元来模拟钉-土之间的相互作用，计算表明该单元能较好地模拟钉-土界面的作用实质。
其四，土钉支护边坡的稳定性验证。土钉支护的边坡需要验证其稳定性，本文采用当前比较流行的强度折减有限元进行了有土钉支护与无土钉支护边坡的稳定性分析，结果比较理想。
The support structure of Soil nailing is one of the support form used in foundation pit. It not only has the common characteristics of foundation pit support form but also has some specialities. In this paper, four aspects of soil nailing were expatiated in detail. Many factors that influence the foundation pit support are considered, and the principle of soil nailing support is analyzed correctly.
(1) Construction mechanics problem The structure shape will be changed along with the construction course. In the course of construction, the external loads will be changed accordingly. Foundation pit engineering is one of the unload problem in the construction mechanics. The computation of excavation load can be regard as the process that the stress of excavation surface is released completely and the excavation surface then changed into the free stress surface. The method of Mana is used to compute the excavation load in this paper. The method of Mana is one of the finite element method, and the method is rather effective.
(2) Active support form The support form of soil nailing can preserve, enhance and impose the soil intension of foundation pit walls. It can change the soil loads into one part of the support construction system. So the soil nailing support can be regard as the initiative support form. The support form has the advantages and can be used widely.
(3)Nailing-soil interaction It is well known that the characteristics of soil is different from the characteristics of soil nailing, and the distortion of them is disagreement. The shearing stress will come into being in the contact surface. The shearing stress is the medium that can transfer the load between soil and soil nailing. It is very important to analyze the principle of deformation, the development of shearing destruct, the process of load transfer and simulate them correctly. In this paper, the interface element is used to simulate the interaction between soil and soil nailing. It is indicated that the interface element can simulate the soil-nailing interface perfectly.
(4) The validation of the slope stability by soil nailing The strength reduction finite element method is used to analyze the stability of the slope timbered by soil nailing and the slope timbered by the traditional support form. It is proved that the stability of the slope timbered by the soil nailing is ideal.
引文
[1] 钱七虎．迎接我国城市地下空间开发高潮[J]．岩土工程学报．1998，20(1)：112-113．
[2] 徐伟，苏宏阳．建筑工程分部分项施工手册．北京：中国计划出版社，1999，5．
[3] 刘建航，候学渊．基坑工程手册[M]．北京：中国建筑工业出版社．1997．
[4] 王梦恕．岩土工程在城区设计、施工的体会[J]．岩土工程界．2000，(1)：12-15．
[5] 陈忠汉，程丽萍编著．深基坑工程．北京：机械工业出版社，1999．
[6] 秦四清，王建党．土钉支护机理与优化设计．北京：地质出版社，1999，5．
[7] 武亚军，卢文阁，栾茂田，候仰杰．深基坑支护结构优化设计探讨．建筑结构，2000．11．
[8] 中华人民共和国行业标准《建筑基坑支护技术规程》(JGJ120-99)．
[9] 欧阳仲春编著．现代土工加筋技术．北京：人民交通出版社，1991：137-138．
[10] 龚晓南，高有潮．深基坑设计施工手册．北京：中国建筑工业出版社，1999，9．
[11] Schlosser, F. & Unterreiner, P. French Research Program CLOUTERRE on Soil Nailing. Geotechnical Special Publication, ASCE, 1992, 30(2): 739-749.
[12] Bruce, D.A & Jewell, R.A. Soil Nailing: Application and Practice-Part 1, Part 2. Ground Engineering, 1986,19(12): 10-15, 1987, 20(1): 21-33.
[13] Juran, I. & Elias, V. Ground Anchors and Soil Nails in Retaining Structures. Foundation Engineering Handbook, Chapter 26, Fang .H. Y. (Ed.), Van Nostrad Beinhold Pub., 1991: 868-906.
[14] Schlosser, F. Soil Nailing in France-Research and Practice, Transportation Research Record 1330, Transportation Research Board, Washington, D.C., 1992.
[15] Plumelle,C. & Schlosser, F. French National Research Project on Soil Nailing Clouterre, Geotechnical Special Publication, ASCE, 1990, (25): 661-675.
[16] Elias, V. & Juran, I. Soil Nailing for Stabilization of Highway Slopes and Excavations. FHWA/RD-89/198, June 1991: 868-905.
[17] Gassler, G & Gudenhus, G. Soil Nailing-Some Aspects of a New Technique, Proc. ICSMEF, 1981, 3: 665-670.
[18] Byrne, R. J. Walkingshaw, J. L. FHWA International Scanning Tour for Geotechnology, September-Octomber 1992, FHWA/PL93/020, June 1993.
[19] Byrne, R. J. Soil Nailing: A Simplified Kinematic Analysis. Geotechnical Special Publication, ASCE, 1992, (30): 751-763.
[20] Bang, S. Investigation of Soil Nailing Systems. Advances in Geotechnical Engineering, Transport Research Record 1396, 1992.
[21] 杨志银．土钉支护技术中的新发展．岩土锚固协会论文集．中国建筑工业出版社，1996．
[22] 曾宪明，黄久松，王作民．土钉支护设计与施工手册．北京：中国建筑工业出版社，2000，8．
[23] 陈肇元，崔京浩主编．土钉支护在基坑工程中的应用．北京：中国建筑工业出版社，1997：1-78．
[24] 陈肇元．深基坑开挖的土钉支护技术(一)、(二)、(三)．地下空间，1995，15(4)：241-249，16(1，2)：1-11，65-75．
[25] 卓家寿，章青著．不连续介质力学问题的界面单元法．北京：科学出版社．2000．
[26] 余志成，施文华编著．深基坑支护设计与施工．北京：建筑工业出版社，1997．
[27] 杨林德，包伟瑜，盛东健著．地下工程施工监测数据管理的研究．第六届全国地基处理学术讨论会暨第二届全国基坑工程学术讨论会论文集，温州，2000．
[28] 宋二祥，陈肇元．土钉支护及其有限元分析．工程勘察，1996，139(2)：1-5．
[29] Sabhahit, N. & Basudhar, P. K. A Generalized Procedure for the Optimum Design of Nailed Soil Slopes, Int. J. for Num. Analy. Methods in Geomech. 1995, 19: 437—452.
[30] Xanthakos, P.P. Abramson, J. W. & Bruce, D. A. Ground Control and Improvement, John Wiely & Sons Pub, 1994: 331-405.
[31] 钱家欢，殷宗泽．土工原理与计算．北京：中国水利水电出版社．1996．5．
[32] 龚晓南主编．土工计算机分析．北京：中国建筑工业出版社，2000，10．
[33] 姜弘道，陈和群．有限单元法的程序设计．北京：水利电力出版社，1989．
[34] 王勖成，邵敏．有限单元法基本原理和数值方法．北京：清华大学出版社，1997．
[35] 胡建林，钟映东．深基坑土钉支护技术．建筑施工，1997，19(4)：13-14．
[36] 陈和群，彭宣茂编著．有限元法微机程序与图形处理．河海大学出版社，1992，9．
[37] (1989)Ugai K. A method of calculation of total factor of safety of slope by elasto-plastic FEM[J]. Soils and Foundations. 1989, 29(2): 190-195.
[38] (1992)Matsui T.and San. K.C. Finite element slope stability analysis by shear strength reduction technique. Soils and foundations. Vol.32, No. 1, 59-70, Mar. 1992.
[39] (1995)Ugai K. and Leshchinsky D. Three-Dimensional limit equilibrium and finite element analysis. Soils and foundations. Vol.35, No.4,Dec. 1995.
[40] (1999)Giffiths D V, Lane P A. Slope stability analysis by finite element [J]. Geotechnique, 1999, 49(3): 387-403.
[41] (1999)Dawson E M, Roth W H. Drescher A. Slope stability analysis by strength reduction [J]. Geotechnique, 1999, 49(6): 835-840.
[42] (2000)Manzari M T, Nour M A. Significanique of soil dilatancy in slope stability analysis [J]. Journal of Geotchnique and Geoenvironmental Engineering. ASCE, 2000, 126(1): 75-80.
[43] (2001)连镇营，强度折减有限元法研究开挖边坡的稳定性．岩土工程学报．2001．23(4)407-411．
[44] 徐水根，胡伟庆，张忠明．软土地层中的复合土钉支护．上海地质，1999，3：12-16．
[2] 徐伟，苏宏阳．建筑工程分部分项施工手册．北京：中国计划出版社，1999，5．
[3] 刘建航，候学渊．基坑工程手册[M]．北京：中国建筑工业出版社．1997．
[4] 王梦恕．岩土工程在城区设计、施工的体会[J]．岩土工程界．2000，(1)：12-15．
[5] 陈忠汉，程丽萍编著．深基坑工程．北京：机械工业出版社，1999．
[6] 秦四清，王建党．土钉支护机理与优化设计．北京：地质出版社，1999，5．
[7] 武亚军，卢文阁，栾茂田，候仰杰．深基坑支护结构优化设计探讨．建筑结构，2000．11．
[8] 中华人民共和国行业标准《建筑基坑支护技术规程》(JGJ120-99)．
[9] 欧阳仲春编著．现代土工加筋技术．北京：人民交通出版社，1991：137-138．
[10] 龚晓南，高有潮．深基坑设计施工手册．北京：中国建筑工业出版社，1999，9．
[11] Schlosser, F. & Unterreiner, P. French Research Program CLOUTERRE on Soil Nailing. Geotechnical Special Publication, ASCE, 1992, 30(2): 739-749.
[12] Bruce, D.A & Jewell, R.A. Soil Nailing: Application and Practice-Part 1, Part 2. Ground Engineering, 1986,19(12): 10-15, 1987, 20(1): 21-33.
[13] Juran, I. & Elias, V. Ground Anchors and Soil Nails in Retaining Structures. Foundation Engineering Handbook, Chapter 26, Fang .H. Y. (Ed.), Van Nostrad Beinhold Pub., 1991: 868-906.
[14] Schlosser, F. Soil Nailing in France-Research and Practice, Transportation Research Record 1330, Transportation Research Board, Washington, D.C., 1992.
[15] Plumelle,C. & Schlosser, F. French National Research Project on Soil Nailing Clouterre, Geotechnical Special Publication, ASCE, 1990, (25): 661-675.
[16] Elias, V. & Juran, I. Soil Nailing for Stabilization of Highway Slopes and Excavations. FHWA/RD-89/198, June 1991: 868-905.
[17] Gassler, G & Gudenhus, G. Soil Nailing-Some Aspects of a New Technique, Proc. ICSMEF, 1981, 3: 665-670.
[18] Byrne, R. J. Walkingshaw, J. L. FHWA International Scanning Tour for Geotechnology, September-Octomber 1992, FHWA/PL93/020, June 1993.
[19] Byrne, R. J. Soil Nailing: A Simplified Kinematic Analysis. Geotechnical Special Publication, ASCE, 1992, (30): 751-763.
[20] Bang, S. Investigation of Soil Nailing Systems. Advances in Geotechnical Engineering, Transport Research Record 1396, 1992.
[21] 杨志银．土钉支护技术中的新发展．岩土锚固协会论文集．中国建筑工业出版社，1996．
[22] 曾宪明，黄久松，王作民．土钉支护设计与施工手册．北京：中国建筑工业出版社，2000，8．
[23] 陈肇元，崔京浩主编．土钉支护在基坑工程中的应用．北京：中国建筑工业出版社，1997：1-78．
[24] 陈肇元．深基坑开挖的土钉支护技术(一)、(二)、(三)．地下空间，1995，15(4)：241-249，16(1，2)：1-11，65-75．
[25] 卓家寿，章青著．不连续介质力学问题的界面单元法．北京：科学出版社．2000．
[26] 余志成，施文华编著．深基坑支护设计与施工．北京：建筑工业出版社，1997．
[27] 杨林德，包伟瑜，盛东健著．地下工程施工监测数据管理的研究．第六届全国地基处理学术讨论会暨第二届全国基坑工程学术讨论会论文集，温州，2000．
[28] 宋二祥，陈肇元．土钉支护及其有限元分析．工程勘察，1996，139(2)：1-5．
[29] Sabhahit, N. & Basudhar, P. K. A Generalized Procedure for the Optimum Design of Nailed Soil Slopes, Int. J. for Num. Analy. Methods in Geomech. 1995, 19: 437—452.
[30] Xanthakos, P.P. Abramson, J. W. & Bruce, D. A. Ground Control and Improvement, John Wiely & Sons Pub, 1994: 331-405.
[31] 钱家欢，殷宗泽．土工原理与计算．北京：中国水利水电出版社．1996．5．
[32] 龚晓南主编．土工计算机分析．北京：中国建筑工业出版社，2000，10．
[33] 姜弘道，陈和群．有限单元法的程序设计．北京：水利电力出版社，1989．
[34] 王勖成，邵敏．有限单元法基本原理和数值方法．北京：清华大学出版社，1997．
[35] 胡建林，钟映东．深基坑土钉支护技术．建筑施工，1997，19(4)：13-14．
[36] 陈和群，彭宣茂编著．有限元法微机程序与图形处理．河海大学出版社，1992，9．
[37] (1989)Ugai K. A method of calculation of total factor of safety of slope by elasto-plastic FEM[J]. Soils and Foundations. 1989, 29(2): 190-195.
[38] (1992)Matsui T.and San. K.C. Finite element slope stability analysis by shear strength reduction technique. Soils and foundations. Vol.32, No. 1, 59-70, Mar. 1992.
[39] (1995)Ugai K. and Leshchinsky D. Three-Dimensional limit equilibrium and finite element analysis. Soils and foundations. Vol.35, No.4,Dec. 1995.
[40] (1999)Giffiths D V, Lane P A. Slope stability analysis by finite element [J]. Geotechnique, 1999, 49(3): 387-403.
[41] (1999)Dawson E M, Roth W H. Drescher A. Slope stability analysis by strength reduction [J]. Geotechnique, 1999, 49(6): 835-840.
[42] (2000)Manzari M T, Nour M A. Significanique of soil dilatancy in slope stability analysis [J]. Journal of Geotchnique and Geoenvironmental Engineering. ASCE, 2000, 126(1): 75-80.
[43] (2001)连镇营，强度折减有限元法研究开挖边坡的稳定性．岩土工程学报．2001．23(4)407-411．
[44] 徐水根，胡伟庆，张忠明．软土地层中的复合土钉支护．上海地质，1999，3：12-16．