摘要
湿陷性黄土地基浸水后的不均匀沉降会使现浇管廊结构产生附加内力,造成管廊结构开裂甚至破坏,严重威胁其运营安全.为深入研究黄土地层湿陷变形对现浇管廊的影响,开展了黄土地层局部浸水湿陷的模型试验.在试验中,设定局部浸水范围,以地基浸水深度为变量,对管廊结构底部位移、土体接触压力、表面应变和地表沉降进行了监测,并分析了其发展趋势.试验结果表明:当局部基底浸水深度达到20 cm,管廊结构在浸水区出现明显的弯曲变形,结构在湿陷区内的最大下沉达到0.57 mm;结构与土体接触压力变化较大区域为湿陷区边缘的管廊底板处;在管廊底部局部浸水发生不均匀沉降时,结构受力形式表现为底板受拉,顶板受压,且越远离管廊中部,所产生的应变越小,拉压应变在湿陷区边缘发生转变;地表也会发生沉降现象,最大沉降值为2.24 mm.试验结果可为湿陷黄土地区现浇管廊的设计和相关病害的防治提供参考.
The uneven settlement of collapsible loess foundation after immersion will cause additional internal forces to the cast-in-place pipe gallery structure,resulting in cracking or even destruction of the pipe gallery structure,which seriously threatens its operation safety.In order to further study the influence of collapsible deformation of loess stratum on cast-in-place pipe gallery,a model test of local immersion collapsible loess stratum was carried out.In the test,the local immersion range was set,and the depth of foundation immersion was used as a variable to monitor the bottom displacement,soil contact pressure,surface strain and surface settlement of the pipe gallery structure,and its development trend was analyzed.The test results show that when the immersion depth of the local basement reaches 20 cm,the tunnel structure has obvious bending deformation in the immersion area,and the maximum subsidence of the structure in the collapsible area reaches 0.57 mm.The area where the contact pressure between the structure and the soil changes greatly is the bottom plate of the pipe gallery at the edge of the collapsible area.When uneven settlement occurs in the local immersion at the bottom of the pipe gallery,the stress form of the structure is that the floor is pulled and the roof is pressed,and the farther away from the middle of the pipe gallery,the smaller the strain is,and the tensile and compressive strain changes at the edge of the collapsible zone.The surface subsidence phenomenon also occurs,and the maximum settlement value is 2.24 mm.The test results of this paper can provide reference for the design of cast-in-place pipe gallery in collapsible loess area and the prevention and control of related disasters.
作者
邓博团
申超凡
郑谢缙
付一帆
DENG Botuan;SHEN Chaofan;ZHENG Xiejin;FU Yifan(School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi′an 710054,China)
出处
《西安建筑科技大学学报（自然科学版）》
北大核心
2024年第2期212-219,共8页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
国家自然科学基金(42177155)
西部绿色建筑国家重点实验室开放基金(LSKF202323)。
关键词
现浇管廊
湿陷性黄土
浸水湿陷
地基沉降
变形规律
cast-in-place pipe gallery
collapsible loess
water immersion collapsibility
foundation settlement
law of deformation
