摘要
以常用的摩尔-库仑强度准则模拟弹塑性区的本构关系,研究小孔扩张问题,推导了扩孔压力和能耗理论解。基于球孔扩张的假设,结合能量理论和非关联流动法则,将扩孔过程视为能量转换问题,进行黏土大应变能耗分析。弹性区采用小应变理论分析。考虑塑性区弹性变形和塑性区大应变的影响,得到了扩孔压力、能耗与扩孔半径的关系。通过与已发表结果比较,验证了所提方法的有效性。最后,研究塑性区弹性变形和大应变对扩孔压力和能耗的影响。结果表明,扩孔压力随剪胀角的增大而增大,外力所做的大部分功在塑性区转化为能量。剪胀角对塑性区域发展和扩孔压力演化影响显著,随着剪胀角的增加,塑性区半径和扩孔压力明显增加。该能耗理论解为揭示注浆、土工试验与贯入桩等方面提供了一种新的分析手段和必要的理论依据。
The constitutive relation of elasto-plastic zone is simulated by Mohr-Coulomb criterion(M-C),and the theoretical solutions of cavity expansion pressure and energy dissipation are derived.Based on the assumption of spherical cavity expansion,combining with energy theory and non-associated flow rule,the process of cavity expansion is regarded as an energy conversion problem,and the large-strain energy dissipation analysis of cohesive-frictional soils is carried out.Firstly,the elastic zone is analyzed by a small-strain theory.Then,considering the effects of elastic deformation and large strain in plastic zone,the relationship among cavity expansion pressure,energy dissipation and radius is obtained.Compared with the published results,the effectiveness of the study is verified.Finally,the effects of elastic deformation and large strain in the plastic zone on cavity expansion pressure and energy dissipation are studied.The results show that the cavity expansion pressure increases with the increase of the dilatancy angle,and most of the work done by the external force is transformed into energy in the plastic zone.The dilatancy angle has a significant effect on the change of the plastic zone and the cavity expansion pressure.With the increase of dilatancy angle,the radius of plastic zone and the cavity expansion pressure increase significantly.The energy dissipation analysis provides a new analytical method and necessary theoretical basis for understanding of the mechanisms of grouting,geotechnical test and driven pile.
作者
李超
莫品强
李树忱
LI Chao;MO Pin-qiang;LI Shu-chen(State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Shenzhen Urban Public Safety and Technology Institute,Shenzhen,Guangdong 518046,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第7期2017-2027,共11页
Rock and Soil Mechanics
基金
中央高校基本科研基金(No.2022QN1019)
江苏省双创博士计划(2022)
国家自然科学面上项目(No.52178374)。
关键词
能耗理论解
球孔扩张
黏土
大应变
energy dissipation
spherical cavity expansion
cohesive-frictional soils
large-strain
