Similarity solution for cavity expansion in thermoplastic soil          下载免费PDF全文

Hang Zhou  Gangqiang Kong  Hanlong Liu  Lyesse Laloui 《国际地质力学数值与分析法杂志》2018,42(2):274-294

This paper presents an analytical solution for cavity expansion in thermoplastic soil considering non‐isothermal conditions. The constitutive relationship of thermoplasticity is described by Laloui's advanced and unified constitutive model for environmental geomechanical thermal effect (ACMEG‐T), which is based on multi‐mechanism plasticity and bounding surface theory. The problem is formulated by incorporating ACMEG‐T into the theoretical framework of cavity expansion, yielding a series of partial differential equations (PDEs). Subsequently, the PDEs are transformed into a system of first‐order ordinary differential equations (ODEs) using a similarity solution technique. Solutions to the response parameters of cavity expansion (stress, excess pore pressure, and displacement) can then be obtained by solving the ODEs numerically using mathematical software. The results suggest that soil temperature has a significant influence on the pressure‐expansion relationships and distributions of stress and excess pore pressure around the cavity wall. The proposed solution quantifies the influence of temperature on cavity expansion for the first time and provides a theoretical framework for predicting thermoplastic soil behavior around the cavity wall. The solution found in this paper can be used as a theoretical tool that can potentially be employed in geotechnical engineering problems, such as thermal cone penetration tests, and nuclear waste disposal problems.  相似文献   

A simple estimation model for basal heave stability of braced excavations in anisotropic clay     

Zhang  Runhong  Goh  Anthony Teck Chee  Li  Yongqin  Liu  Hanlong  Wang  Lin  Chen  Zhixiong  Zhang  Wengang 《Acta Geotechnica》2022,17(12):5789-5800

Acta Geotechnica - The basal heave stability of the excavation and support system is a major concern to geotechnical design engineers, particularly in soft clay deposits. Conventional methods for...  相似文献   

Mechanical properties of biocement formed by microbially induced carbonate precipitation     

Ma  Guoliang  Xiao  Yang  Fan  Wenjun  Chu  Jian  Liu  Hanlong 《Acta Geotechnica》2022,17(11):4905-4919

Acta Geotechnica - The failure of biocemented sand can be attributed to the breakage of biocement and the exfoliation of precipitates from sand surfaces. Therefore, optimizing the mechanical...  相似文献   

~(40)/Ar~(39)Ar Ages of Auriferous Quartz Veins from the Fengyang and Zhangbaling Regions and Their Geological Significance     

应汉龙  赵利清 《中国地球化学学报》2003,22(3)

1IntroductionAuriferousquartzveinsarecommonintheFengyangandZhangbalingregionsofAnhuiProvinceandtheyconstitutetheRongdu ,Zhuding ,Dagongshan ,MaoshanandShangchenggolddepositsandalotofgoldperspectives .TheRb SrisochronagesofalterationmineralsfromtheRongduandDagongshangolddepositsare (10 9.0± 4 .4 )Maand (15 3.76± 11.2 )Ma ,respectively (Dongetal .,1995 ) .Thereisalargedifferenceinagebetweenthetwogolddeposits ,butitcanbeseenthatthegolddepositswereformedinLateJurassictoEarlyCretaceous .A…  相似文献   

论胶西北河西金矿床成因及其动力学条件   总被引：6，自引：0，他引：6  

徐贵忠  应汉龙  周瑞  佘宏全  闫臻  王艺芬  李兵 《矿床地质》2002,21(3):246-255

胶东河西金矿床属于典型的蚀变岩型金矿床.金矿体赋存于玲珑黑云母花岗岩体内,并受北东向断裂构造带所控制.87Sr/86Sr的初始比值表明,玲珑黑云母花岗岩和郭家岭花岗闪长岩均为壳源深熔花岗岩.地质和同位素年代学资料表明,金成矿作用发生在早白垩世.据硫、氧同位素组成判断,河西金矿床的成矿作用可能与郭家岭花岗闪长岩的流体活动有关,其成矿温度以中温为主,成矿压力为(1*!200～1*!400)×105 Pa.河西金矿床的花岗岩、蚀变岩和矿石的稀土与微量元素分布模式明显相似,说明它们有着共同的成因,与壳熔花岗岩岩浆作用有关.  相似文献   

A novel analytical approach for predicting the noncylindrical pile penetration‐induced soil displacement in undrained soil by combining use of cavity expansion and strain path methods          下载免费PDF全文

Hang Zhou  Hanlong Liu  Jingrong Yuan 《国际地质力学数值与分析法杂志》2018,42(11):1270-1305

Since development of cavity expansion theory and strain path method, almost all the conventional analyses of pile penetration problem have been based on circular cross section penetrometer. However, noncylindrical pile (with noncircular cross section) is also required in geotechnical engineering such as rectangular cross‐sectional pile, X‐sectional cast‐in‐place concrete pile, H‐shaped steel pile, prefabricated vertical drains, and flat dilatometer. This paper presents a novel and general analytical approach for capturing the soil deformation mechanism around the pile with arbitrary cross section. The penetration problem is simulated by a new 2‐dimensional (radial and circumferential) cavity expansion model. Based on the theoretical framework of strain path method, the kinematics (velocity field) of the noncylindrical cavity expansion is reduced to solve the Laplace equation with arbitrary velocity boundary conditions by using the conformal mapping technique. Then, solutions for the strain and displacement, which could consider the large deformation effect, are obtained by the integration of the strain rate and velocity along the streamline. The analytical solution is validated by comparing the degenerate solution of this study with conventional circular (cylindrical) cavity expansion theory. Subsequently, typical numerical examples for the deformation mechanism of elliptical and rectangular cavity expansion are presented to prove the advantage of the proposed new solution particularly in capturing the noncylindrical symmetric displacement field. A brief application of the proposed new analytical solution to the interpretation of the smear effect of prefabricated vertical drain installation confirms its useful in geotechnical engineering.  相似文献   

An elastoplastic constitutive model for rockfills incorporating energy dissipation of nonlinear friction and particle breakage     

Mengcheng Liu  Yufeng Gao  Hanlong Liu 《国际地质力学数值与分析法杂志》2014,38(9):935-960

A new elastoplastic model is developed for rockfills within the general critical state framework incorporating the state parameter. Two state functions are proposed to characterize the evolution of volume dilation and strain softening of rockfills, and a modified breakage index based on the concept of Hardin's relative breakage is defined to describe the progressive crushing of rockfills. The nonassociated plastic flow rule is derived from a state dependent dilatancy equation, and it incorporates energy dissipation due to intrinsic nonlinear friction and particle breakage upon shearing. Thus, their couple effect on the plastic deviatoric and volumetric deformation of rockfills is taken into account in the current model. The numerical analyses are carried out for a series of drained triaxial tests on the modeled rockfills at various consolidation pressures and stress paths. The volume dilation/contraction and strain softening/hardening of rockfills are accurately predicted by the proposed model, and the particle breakage and nonlinear critical state shear strength of rockfills are also well captured. The research findings indicate that the current model is applicable to represent the complex stress–strain–volume change behavior of rockfills in general. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

饱和南京细砂永久应变势模型的试验研究     

王炳辉  陈国兴  刘汉龙  胡庆兴 《世界地震工程》2011,27(2)

土单元永久应变势的预测模型是土动力学的重要研究内容之一。现有的土单元永久应变势模型没有反映振动孔压增长的影响,难以合理解释地震动作用引起的饱和砂土地基永久变形一般是由土层软化或再固结变形所致的机理。基于饱和南京细砂永久变形动三轴试验结果的有效应力状态分析,研究了试样的永久变形与振动孔压增长的关系,建立了一个能反映振动孔压增长影响的土单元永久应变势模型,给出了土单元永久应变势的数学表达式,分析了土单元永久应变势模型参数的影响因素。初步的验证性试验表明:模型预测与试验测得的试样永久应变势与振动孔压增长曲线比较接近,说明该模型具有一定的合理性。  相似文献   

Biocarbonation of reactive magnesia for soil improvement     

Yang  Yang  Ruan  Shaoqin  Wu  Shifan  Chu  Jian  Unluer  Cise  Liu  Hanlong  Cheng  Liang 《Acta Geotechnica》2021,16(4):1113-1125

Acta Geotechnica - This paper presents a new microbial technique for soil improvement through microbially induced carbonate precipitation (MICP) incorporating with reactive magnesia cement (RMC)....  相似文献   

Geotechnical properties of 3D-printed transparent granular soil     

Li  Yingzhen  Zhou  Hang  Liu  Hanlong  Ding  Xuanming  Zhang  Wengang 《Acta Geotechnica》2021,16(6):1789-1800

This paper proposes a 3D-printed transparent granular soil technique based on the contour rotation interpolation method, 3D printing and transparent soil technologies. Laboratory tests, including one-dimensional compression, direct shear and triaxial compression tests, are assessed for mechanical properties of 3D-printed transparent granular soil. The results show that 3D-printed transparent granular soil can be used to consider the effect of shape on macromechanical soil properties, which is an advantage that cannot be achieved by the previously presented transparent soil techniques. Subsequently, a simple model test of rigid flat plate penetration into transparent granular soil is performed. The obtained soil displacements using the PIV technique are compared with the classical shallow strain path method solution. This comparison indicates that the proposed 3D-printed transparent granular soil can capture the soil deformation pattern, although the accuracy needs to be further improved. The proposed 3D-printed transparent granular soil technique could be used for model test that needs to consider the shape of sand particle.

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