现场压实条件下的土石混合料变形特性试验研究  

Experimental study on deformation characteristics of earth-rock mixed materials under condition of on-site compaction

作　　者：段玉昌 顾一鸣 洪磊 梁睿斌 徐祥 DUAN Yuchang;GU Yiming;HONG Lei;LIANG Ruibin;XU Xiang(Jiangsu Jurong Pumped Storage Co.,Ltd.,Jurong 212400,Jiangsu,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,Jiangsu,China;International Joint Laboratory of Long-term Behaviour&Environmentally Friendly Rehabilitation Technologies on Dams,Nanjing 210098,Jiangsu,China)

机构地区：[1]江苏句容抽水蓄能有限公司,江苏句容212400 [2]河海大学水利水电学院,江苏南京210098 [3]大坝长效特性及环保修复技术中西联合实验室,江苏南京210098

出　　处：《水利水电技术（中英文）》2021年第11期239-246,共8页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金(U1765205,51979091,52009036)。

摘　　要：为了解土石混合料在现场压实条件下的变形特性,结合句容抽水蓄能电站上水库库盆填筑工程,对5种不同的土石混合料进行现场压实,并开展原位平板载荷试验;然后,利用Bussinesq解求得不同竖向压力下的变形模量。研究表明:P5(粒径>5 mm的颗粒)含量较高的上库开挖料经现场压实后,其承载力和变形模量均大于P5含量低的下库开挖料。土石混合料在现场压实后处于超固结状态,具有较大的前期固结应力。当竖向应力较小时,土体处于弹性变形阶段,初期加载沉降变形较小,当竖向应力超过前期固结应力后,土体进入塑性变形阶段,后续加载沉降速率明显加快。含水率较低、P5含量高的土石混合料在薄层重型激振碾压后会形成强度较高的表面硬壳层;而含水率较高、P5含量较低的土石混合料,在弹性变形阶段具有较为显著的压硬性,当进入弹塑性变形阶段后,其变形模量则随着竖向应力的增大而减小。本文所得到的现场压实土石混合料压缩变形模量对于类似工程设计具有一定的参考作用。In order to understand the deformation characteristics of the earth-rock mixed materials under the condition of on-site compaction,five different kinds of earth-rock mixed materials are compacted on site,and then the relevant in-situ plate load tests are carried out in combination with the reservoir basin filling construction of the upper reservoir for Jurong Pumped Storage Hydropower Station.And then,the deformation moduli under different vertical pressures are obtained with Bussinesq′s solution.The study results show that both the bearing capacity and the deformation modulus of the materials excavated from the upper reservoir with higher content of P5(grains with particle size>5mm)are higher than those of the materials excavated from the lower reservoir with lower content of P5 after the on-site compaction.The earth-rock mixed materials are to be in an over-consolidated state with larger pre-consolidation stress after the on-site compaction.When the vertical stress is smaller,the earth mass is to be in an elastic deformation phase with smaller initial loading settlement deformation,and the earth mass is to come into the plastic deformation phase with significant acceleration of subsequent loading settlement rate when the vertical stress surpasses the pre-consolidated stress.A surface hard shell layer is to be formed on the earth-rock mixed materials with lower water content and higher P5 content after heavy vibration rolling in thin layers,while the earth-rock mixed materials with higher water content and lower P5 content has more significant compacted hardness in the elastic deformation phase and its deformation modulus is to be decreased along with the increase of the vertical stress after entering the elastic deformation phase.The compressive deformation modulus of the on-site compacted earth-rock materials obtained herein has a certain referential value for the design of the similar project concerned.

关 键 词：土石混合料 现场载荷试验 变形模量 压实质量 库盆填筑施工 

分 类 号：TV213.4[水利工程—水文学及水资源]