1、书书书Journal of Engineering Geology工程地质学报10049665/2022/30(6)-1914-15于庆博，王清，李兴华 2022 土结构性的动态特征与概念表达J 工程地质学报，30(6):19141928 doi:1013544/jcnkijeg20220761Yu Qingbo，Wang Qing，Li Xinghua 2022 Dynamic characteristics and concept expression of soil structureJ Journal of Engineering Geology，30(6):19141928 doi:
2、1013544/jcnkijeg20220761土结构性的动态特征与概念表达*于庆博王清李兴华姚萌孙逊夏玮彤舒杭刘经王照希(吉林大学建设工程学院，长春 130026，中国)(自然资源部复杂结构岩土体灾变防控工程技术创新中心，长春 130021，中国)(中国电力工程顾问集团中南电力设计院，武汉 430071，中国)摘要随着国家重大工程的开发建设，大量的基础工程应运而生，部分结构物对地基土变形问题尤为敏感，需要专门研究以确保重大工程安全。然而，土体的天然的结构性与固结状态的差异，不仅会对土体的压缩特性和相关力学指标产生重要影响，也给变形的分析与沉降计算带来挑战。厘清土的结构性与固结状态的表现形式，
3、探讨两者之间的辩证关系，将对工程实践有一定的实际意义。基于课题组多年研究成果，立足于土的侧限压缩特征，本文着重分析了土体反常“超固结”特征的成因机制，讨论了结构性的动态变化，并尝试给出了结构性的概念表达。初步得到以下几点认识:(1)土的结构性产生的实质包括颗粒排列和结构连结两方面要素。颗粒排列的紧密程度代表固相成分的空间分布特征，是包括固结压力在内的多种作用力的合并体现;结构连结是土颗粒间相互作用力的总和，其在侧限压缩条件下，主要表现为抵抗变形的结构强度。一般来说，所有土均有不同程度的结构性，包括原状土与重塑土;(2)土的颗粒排列和结构连结存在动态的耦合关系。土体与应力历史不符的“超固结”性质
4、正是来自结构连结对土骨架的差异“强化”以及除自重荷载外其他作用力对土体的压密作用;(3)提出了考虑附加排列效应 Pa的结构屈服压力 k的概念表达形式，即 k=Pc+Pa+q。Pc与 Pa共同反映颗粒排列特征，由 q 反映结构强度。相关成果可能为土体力学特性的评价与分析提供一些参考。关键词侧限压缩;颗粒排列;结构连结;结构强度;附加排列效应中图分类号:P642.3文献标识码:Adoi:1013544/jcnkijeg20220761*收稿日期:20221101;修回日期:20221130基金项目:国家自然科学基金项目(资助号:41820104001)This research is suppor
5、ted by the National Natural Science Foundation of China(Grant No 41820104001)第一作者简介:于庆博(1992)，男，博士，讲师，主要从事土体工程方面的研究 E-mail:yuqbjlueducn通讯作者简介:王清(1959)，女，博士，教授，博士生导师，主要从事工程地质方面的研究 E-mail:wangqingjlueducnDYNAMIC CHAACTEISTICS AND CONCEPT EXPESSION OF SOILSTUCTUEYU QingboWANG QingLI XinghuaYAO MengSUN
6、XunXIA WeitongSHU HangLIU JingWANG Zhaoxi(College of Construction Engineering，Jilin University，Changchun 130026，China)(Engineering Technology Innovation Center for Disaster Prevention of Complex Structural ock and Soil Masses，Ministry of Naturalesources，Changchun 130021，China)(Central Southern China
7、 Electric Power Design Institute Co，Ltd of China Power Engineering Consulting Group，Wuhan 430071，China)AbstractWith the development and construction of national major projects，a large number of foundation projectsemerged as the times require Some structures are particularly sensitive to the deformat
8、ion of foundation soil，whichrequires special research to ensure the safety of related projects However，the differences of the natural structureand consolidation state of soil can not only present an important impact on the compression characteristics and rele-vant mechanical indicators of soil，but a
9、lso bring challenges to the analysis of deformation and settlement calcula-tion It would be of certain practical significance for engineering practice to clarify the combined manifestation ofsoil structure and consolidation state，and to discuss the dialectical relationship between them Based on the
10、previ-ous studies of research group，as well as the confined compression characteristics of soil，this paper analyzes themechanism of the abnormalover-consolidationcharacteristics of soil，discusses the dynamic changes of the struc-ture，and attemptes to give the concept pattern of soil structure The fo
11、llowing preliminary understandings are pres-ented:(1)The essence of soil structure includes particle arrangement and structural connection The compactness ofparticle arrangement reflects the spatial distribution of solid components，which is considered as the combined em-bodiment of multiple forces i
12、ncluding consolidation pressure The structural connection refers to the sum of the inter-action forces between soil particles，which is characterized as the structural strength to resist deformation duringconfined compression Generally speaking，all soils including undisturbed soil and remolded soil h
13、ave different de-grees of structure(2)There is a dynamic coupling relationship between particle arrangement and structural connec-tion of soil The over-consolidation property of soil，inconsistent with the stress history，results from the differentialstrengthening derived by structural connection to s
14、oil skeleton In addition，the compaction of soil derived by otherforces except self-weight also plays an important role(3)The concept expression of structural yield pressure k，considering additional arrangement effect Pa，is proposed，i e k=Pc+Pa+q Pcand Pajointly reflect theparticle arrangement charac
15、teristics，and q represents the structural strength The related results may provide somereference for the evaluation and analysis of soil mechanical propertiesKey wordsConfined compression;Particle arrangement;Structural connection;Structural strength;Additionalarrangement effect0引言随着“一带一路”倡议与“西部大开发”
16、等举措的持续推进，与发展机遇一同涌现的还有复杂的土体工程地质灾变问题，重大工程建设对地基土的沉降变形问题尤为敏感。欲评价地基土的沉降变形与稳定时间，必须研究土的压缩变形量与压缩进程，在此过程中先期固结压力与超固结比是十分关键的力学指标。先期固结压力常用 Pc表示，一般是指天然土层历史上受到过的最大固结压力;先期固结压力与现有土的有效覆盖压力之比称之为超固结比，记作 OC，用来定量描述土的天然压密状态(唐大雄等，1999)。然而，土层在沉积过程中受多种物理化学作用的综合影响，在土颗粒接触处会产生一定的固化连结键(沈珠江，1998)，这种成岩作用使土具有一定的结构性(齐吉琳等，2006)，其对力学特性的影响是十分复杂的。许多学者从不同角度切入，探究了土体的结构性与压缩特性的关联:如孔径分布和渗透性(Nagaraj et al，1998)、围压与胶结程度(Hor-pibulsuk et al，2010)、固结压力与制样方式(陈波等，2017)等等。事实上，土体的压缩特性的确会明显受到土结构性的影响(王常明等，2001;陈存礼等，2014;Lyu et al，2020)，进而影响压缩性指标判断
