| 花岗岩风化料弃土快速堆填过程中不排水抗剪强度评估 |
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| 引用本文： | 詹良通,孙倩倩,郭晓刚,陈锐,陈云敏.花岗岩风化料弃土快速堆填过程中不排水抗剪强度评估[J].岩土力学,2021(1):50-58. |
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| 作者姓名： | 詹良通 孙倩倩 郭晓刚 陈锐 陈云敏 |
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| 作者单位： | ;1.浙江大学岩土工程研究所;2.浙江大学软弱土与环境土工教育部重点实验室;3.哈尔滨工业大学深圳研究生院深圳市城市与土木工程防灾减灾重点实验室 |
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| 基金项目： | 国家自然科学基金青年基金项目(No.51809230);浙江省重点研发计划项目(No.2019C03107)。 |
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| 摘 要： | 沿海沿江城市地下开挖产生的工程渣土含泥量大、含水率高且较松散,主要运往渣土场进行堆填处置。由于产量巨大而处置场地有限,许多渣土场在运营过程中存在堆填速度快、缺乏排水设施、超高超库容堆填等问题,容易引发堆填体失稳事故。目前对于非饱和工程渣土堆体在快速堆填过程中的失稳机制认识尚不清晰,尤其是对这一过程中的高饱和度工程渣土强度增长规律缺乏足够的认识。以深圳红坳渣土场填料——花岗岩风化料(CDG)填土为研究对象,对不同初始饱和度土样进行三轴不排水不排气等向压缩和剪切试验,结果表明:非饱和CDG填土不排水抗剪强度随围压增大呈非线性增长,增长速率与试样初始饱和度密切相关;当土样压缩后的饱和度超过0.7,不排水强度随围压的增长速率显著降低。基于有效固结应力法的原理,结合Hilf孔压公式和修正剑桥模型,提出了一种工程渣土不排水抗剪强度估算方法,并通过与试验结果对比验证了该方法对初始饱和度高于0.6的CDG填土的适用性。利用该方法确定的不排水强度cu与正应力σn的关系可应用于高饱和度工程渣土快速堆填中的稳定性分析。
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| 关 键 词： | 工程渣土 渣土场 不排水抗剪强度 孔压分析 强度估算方法 |
Estimation of undrained shear strength of completely decomposed granite waste during rapid landfilling |
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| ZHAN Liang-tong,SUN Qian-qian,GUO Xiao-gang,CHEN Rui,CHEN Yun-min.Estimation of undrained shear strength of completely decomposed granite waste during rapid landfilling[J].Rock and Soil Mechanics,2021(1):50-58. |
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| Authors: | ZHAN Liang-tong SUN Qian-qian GUO Xiao-gang CHEN Rui CHEN Yun-min |
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| Institution: | (Geotechnical Research Institute,Zhejiang University,Hangzhou,Zhejiang 310058,China;MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou,Zhejiang 310058,China;Shenzhen Key Laboratory of Urban and Civil Engineering for Disaster Prevention and Mitigation,Shenzhen Graduate School,Harbin Institute of Technology,Shenzhen,Guangdong 518055,China) |
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| Abstract: | The construction waste generated by underground excavation in coastal cities has the characteristics of high fine content, high water content and looseness. Landfilling is the most common method for disposal of such construction waste. As the waste production exceeds the capacity of disposal, many of the construction waste dumps have the problems of fast filling, lack of drainage facilities, overload of landfill capacity and over height, which are likely to cause safety accidents such as landslide. These irregulated operations reflect the poor understanding of the strength growth law of the high saturation degree waste during rapid landfilling. In this paper, completely decomposed granite(CDG) waste is taken from the site of Shenzhen Hong’ao landslide, and a series of triaxial tests with the drain and exhaust valves closed is performed on the samples with different initial saturations. The experimental results reveal that the undrained shear strength of CDG nonlinearly increases with the increase of confining pressure, and the growth rate is closely related to the initial saturation of the sample. The growth rate of the undrained shear strength significantly decreases as the saturation exceeds 0.7. Inspired by the principle of undrained strength analysis, an estimation method for undrained shear strength is proposed, in which Hilf’s equation and the modified Cam-clay model are employed. The proposed method is verified to be capable for predicting the undrained shear strength for CDG with an initial saturation exceeding 0.6 by comparing the estimation results with the measured values in the triaxial tests. The undrained shear strength cu and normal stress σn determined by the estimation method can be used in the stability analysis of waste dump with high filling rate. |
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| Keywords: | construction waste waste dump undrained shear strength pore pressure analysis estimation method of shear strength |
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