基于弹性模量标定的基坑支护结构位移计算
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摘要
土钉支护技术以其简便、迅速、经济等独特优点被广泛应用于深基坑工程,但和工程实践相比其设计理论落后较多,尤其是在计算支护结构位移时缺乏较符合实际的计算方法,经验性的设计方法在基坑支护中往往占据着重要作用。目前,在土钉支护理论研究方面主要有两种方法,一是极限平衡法,二是有限元法。本文在学习前人研究成果的基础之上,以西安水晶·卡芭拉基坑工程为例,结合基坑变形实测数据,用有限元法对基坑深度范围内土体的弹性模量进行了标定,将标定后的弹性模量代入相似基坑,检验其标定结果的正确性。结果显示,标定后的弹性模量在新基坑具有适用性,表明在基坑深度影响范围内,用有限元法对土层弹性模量进行标定是合理的,标定后的模拟结果能较好地反应基坑支护过程的实际情况,这为基坑支护结构位移计算提供了一种新的参考思路。
Because of the simple, rapid, economic and other unique advantages, soil nailing support technology is widely used in deep foundation pit engineering, but its design theory lags far behind engineering practice, especially lack of practical calculation method when calculating the displacement of support structure and empirical design methods play an important role in foundation pit support. At present, there are mainly two methods in the study of soil nailing theory, one is the limit equilibrium method and the other one is FEM analysis. On the basis of learning the achievements of previous researchers, taking the deep foundation pit engineering of the Crystal Kabala project in Xi'an as an example, and combining the in-situ monitoring data of the foundation pit, the FEM analysis is used to calibrate the elastic modulus. Bring the calibrated elastic modulus to a similar foundation pit, and its correctness is tested. The results show that the calibrated elastic modulus has the applicability in new foundation pit, and it's reasonable for using FEM analysis to calibrate the elastic modulus of the soil within the influence depth of the foundation pit. The calibrated simulation results can better reflect the actual situation of the foundation pit supporting process, which provides a new reference for calculating the displacement of foundation pit support structure.
Because of the simple, rapid, economic and other unique advantages, soil nailing support technology is widely used in deep foundation pit engineering, but its design theory lags far behind engineering practice, especially lack of practical calculation method when calculating the displacement of support structure and empirical design methods play an important role in foundation pit support. At present, there are mainly two methods in the study of soil nailing theory, one is the limit equilibrium method and the other one is FEM analysis. On the basis of learning the achievements of previous researchers, taking the deep foundation pit engineering of the Crystal Kabala project in Xi'an as an example, and combining the in-situ monitoring data of the foundation pit, the FEM analysis is used to calibrate the elastic modulus. Bring the calibrated elastic modulus to a similar foundation pit, and its correctness is tested. The results show that the calibrated elastic modulus has the applicability in new foundation pit, and it's reasonable for using FEM analysis to calibrate the elastic modulus of the soil within the influence depth of the foundation pit. The calibrated simulation results can better reflect the actual situation of the foundation pit supporting process, which provides a new reference for calculating the displacement of foundation pit support structure.
引文
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[3] 王曙光.深基坑支护事故处理经验录[M].北京:机械工业出版社,2005.Wang Shuguang. Experience in dealing with accidents of deep foundation pit support[M].Beijing: China Machine Press,2005. (in Chinese)
[4] 李建光,祁慧君.地基土模量的取值方法及其在有限元计算中的应用[J].工程勘察,2008,(S2):68～70.Li Jianguang, Qi Huijun. The method of determining the modulus of foundation soil and application in the finite element calculation[J]. Geotechnical Investigation & Surveying, 2008,(S2):68～70. (in Chinese)
[5] 杨青.桩锚支护结构有限元分析[J].建筑技术与应用,2017,(5):3～5.Yang Qing. Finite element analysis of pile-anchor supporting structure[J]. Research & Application of Building Materials, 2017,(5):3～5. (in Chinese)
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