CAJ | 학술논문

通过对常规三轴仪进行改装，开展最大竖向应变达50%的城市固体废弃物(MSW)三轴剪切试验。试验表明：大应变条件下MSW试样发生破坏且其破坏应变随填埋深度增大而减小。通过组分分离得到MSW的基本相和加筋相，并对其分别进行三轴固结排水剪切(CD)试验，发现其应力-应变曲线均呈应变硬化型。在此基础上，对基本相进行筛分，并结合不同粒径粒组的微观结构阐述基本相中有机纤维体的存在形式及其加筋作用机制。进一步对各粒组进行CD试验，发现除粒径小于0.075 mm的粒组外其余粒组的应力-应变关系均表现为应变硬化。通过基本相灼烧前后的CD试验比较，发现有机纤维体在应变达到一定程度后才开始发挥加筋作用，且剪切过程中伴随着纤维体断裂以及纤维体与颗粒间滑移。最后，基于MSW的三轴剪切试验结果，分别对三轴固结不排水剪切(CU)试验和CD试验抗剪强度参数的确定方法进行探讨。
통과대상규삼축의진행개장，개전최대수향응변체50%적성시고체폐기물(MSW)삼축전절시험。시험표명：대응변조건하MSW시양발생파배차기파배응변수전매심도증대이감소。통과조분분리득도MSW적기본상화가근상，병대기분별진행삼축고결배수전절(CD)시험，발현기응력-응변곡선균정응변경화형。재차기출상，대기본상진행사분，병결합불동립경립조적미관결구천술기본상중유궤섬유체적존재형식급기가근작용궤제。진일보대각립조진행CD시험，발현제립경소우0.075 mm적립조외기여립조적응력-응변관계균표현위응변경화。통과기본상작소전후적CD시험비교，발현유궤섬유체재응변체도일정정도후재개시발휘가근작용，차전절과정중반수착섬유체단렬이급섬유체여과립간활이。최후，기우MSW적삼축전절시험결과，분별대삼축고결불배수전절(CU)시험화CD시험항전강도삼수적학정방법진행탐토。
A series of triaxial shear tests on municipal solid waste(MSW) with the maximum vertical strain of approximately 50% were carried out by a modified triaxial apparatus. The test results show that MSW samples failed under large-strain condition and the failure strain decreases with the increasing of the landfill depth. The basic and reinforced phases of MSW were separated and triaxial consolidated drained(CD) shear tests were carried out on each phase. The results show that the stress-strain curves of both basic and reinforced phases have the strain-hardening characteristics. The structural formation and reinforcement effect of the organic fibers in basic phase were described through sieving and microscopic observation on granule groups. Then CD tests of several granule groups were carried out and the results demonstrate that every group has a strain-hardening stress-strain curve except the group with particle diameter smaller than 0.075 mm. The stress-strain curves of the basic phase before and after burned were compared,showing that the organic fibers will not play the reinforcement effect until a certain value of strain is reached. Fiber fracture and slipping along the interface seem to exist during shearing. Finally,based on the results of triaxial shear tests,methods for determining the shear strength parameters of triaxial consolidated undrained shear(CU) and CD tests were discussed respectively.