›› 2018, Vol. 39 ›› Issue (10): 3763-3772.doi: 10.16285/j.rsm.2017.1485

• 岩土工程研究 • 上一篇    下一篇

天津滨海地区深部黏土层弹塑性变形特征与地面沉降关系研究

杨吉龙1, 2,袁海帆1, 2,胡云壮1, 2,胥勤勉1, 2,施佩歆1, 2,陈永胜1, 2   

  1. 1. 中国地质调查局 天津地质调查中心,天津 300170;2. 中国地质调查局 泥质海岸带地质环境重点实验室,天津 300170
  • 收稿日期:2017-08-12 出版日期:2018-10-11 发布日期:2018-11-04
  • 作者简介:杨吉龙,男,1980年生,硕士,高级工程师,主要从事水文地质及第四纪地质研究工作。
  • 基金资助:
    中国地质调查局项目(No. 121201006000150009,No. 121201006000182401)。

Relationship between elastoplastic deformation of deep clay and land subsidence in Tianjin coastal area

YANG Ji-long1, 2, YUAN Hai-fan1, 2, HU Yun-zhuang1, 2, XU Qin-mian1, 2, SHI Pei-xin1, 2, CHEN Yong-sheng1, 2   

  1. 1. Tianjin Centre, China Geological Survey, Tianjin 300170, China; 2. Key Laboratory of Muddy Coast Geo-environment, China Geological Survey, Tianjin 300170, China
  • Received:2017-08-12 Online:2018-10-11 Published:2018-11-04
  • Supported by:
    This work was supported by the Project of China Geological Survey (121201006000150009, 121201006000182401).

摘要: 利用在滨海新区施工的2眼全取芯钻孔(G2和G3),通过原状土样工程特性指标测试、固结压力试验、0-P0反复加、卸荷试验及地面沉降分层标监测数据分析等,系统阐述了滨海地区深部黏性土层弹塑性变形特征与地面沉降的关系。结果表明:天津滨海地区100 m以浅主要为欠固结土层;100~400 m土层处于超固结和微超固结状态,主要是由过去地下水超量开采造成的;400 m以下土层以正常固结为主。G2和G3孔不同层位黏性土层在反复加、卸荷试验过程中表现出塑性变形量逐渐减小,而弹性变形量几乎不变,与反复加、卸荷次数无关,表明黏性土层在水位反复升降条件下,逐渐变为以弹性变形为主。黏性土层这种特性显示,在地下水位反复升降多次后,黏性土层将会逐渐变成弹性体,在水位恢复时,将产生同步回弹,对防治地面沉降具有重要意义。分析弹塑性变形与黏性土层深度、天然含水率和黏粒含量的相关性发现:弹性变形量与黏性土层深度、天然含水率及黏粒含量呈正相关性;塑性变形量与深度相关性不明显,与天然含水率和黏粒含量呈负相关性。

关键词: 天津滨海地区, 黏性土层, 弹塑性变形, 地面沉降

Abstract: Two boreholes of G2 and G3 were drilled at Tanggu and Dagang in Tianjin, and undisturbed samples were extracted at various depths. Through laboratory test of all soil samples, this study measured the physical and mechanical properties and conducted consolidation test and repeated loading and unloading tests for clayey soils. By analyzing the test results, this study delineated the characteristics and influence factors of elastic-plastic deformation. Study results indicate that clayey soils in depth less than 100 m are under-consolidated soft soil. Clayey soils in depth from 100 m to 400 m are in the states of over-consolidated or slightly over-consolidated, which causes by long-term over-exploitation of groundwater in the past. Deep clayey soils in depth more than 400 m show the state of normal consolidated. Based on the repeated loading and unloading tests of clayey soils in boreholes G2 and G3, it is found that plastic deformation decreases gradually and elastic deformation remains unchanged, independent on repeating times. The test results also suggest that clayey soils will gradually become an elastic body in the process of groundwater fluctuation, and deformation will rebound when groundwater recovers. By analyzing correlation between elastic-plastic deformation and depth, natural moisture content and clay content of clayey soil, it is found that elastic deformation shows positive correlation with depth, natural moisture content and clay content, and plastic deformation shows negative correlation with natural moisture content and clay content and no obvious correlation with depth.

Key words: Tianjin coastal area, clayey soil, elastic-plastic deformation, land subsidence

中图分类号: 

  • TU 442
[1] 徐进, 王少伟, 杨伟涛. 水位变化下可压缩土层的黏弹性耦合变形分析[J]. 岩土力学, 2020, 41(3): 1065-1073.
[2] 罗 跃,叶淑君,吴吉春,. 三维区域地面沉降数值模拟[J]. , 2018, 39(3): 1063-1070.
[3] 杨建民,霍王文,. 线状和面状群井抽水导致场外地面沉降呈s-lnr线性关系[J]. , 2018, 39(10): 3565-3572.
[4] 崔庆龙 ,沈水龙 ,吴怀娜 ,许烨霜 , . 广州岩溶地区深基坑开挖对周围环境影响的研究[J]. , 2015, 36(S1): 553-557.
[5] 杨吉龙 ,曹国亮 ,李 红 ,李 静 ,胡云壮 , 胥勤勉 ,秦雅飞 ,杜 东 ,方 成,. 天津滨海地区晚新生代地层自然固结与地面沉降研究[J]. , 2014, 35(9): 2579-2586.
[6] 侯公羽 ,李晶晶 ,杨 悦 ,王亚潇 ,李庆伟 ,梁永辉,. 围岩弹塑性变形条件下锚杆、喷混凝土和U型钢的支护效果研究[J]. , 2014, 35(5): 1357-1366.
[7] 王启耀 ,彭建兵 ,蒋臻蔚 ,滕宏泉,. 西安典型段地面沉降分层标观测及数值模拟[J]. , 2014, 35(11): 3298-3302.
[8] 徐玉龙 ,杨春和 ,李银平 ,施锡林 ,孔君凤 ,李浩然,. 基于改进的Mogi模型对樟树盐矿采空区地面沉降的分析[J]. , 2014, 35(10): 2894-2900.
[9] 林存刚 吴世明 张忠苗 刘俊伟 李宗梁 . 盾构掘进速度及非正常停机对地面沉降的影响[J]. , 2012, 33(8): 2472-2482.
[10] 侯公羽,李晶晶. 弹塑性变形条件下围岩-支护相互作用全过程解析[J]. , 2012, 33(4): 961-970.
[11] 许烨霜,马 磊,沈水龙. 上海市城市化进程引起的地面沉降因素分析[J]. , 2011, 32(S1): 578-0582.
[12] 魏 纲,陈伟军,魏新江. 双圆盾构隧道施工引起的地面沉降预测[J]. , 2011, 32(4): 991-0996.
[13] 黎永索 ,张可能 ,黄常波 ,李 钟 ,邓美龙. 管幕预筑隧道地表沉降分析[J]. , 2011, 32(12): 3701-3707.
[14] 蒋臻蔚,彭建兵,王启耀. 西安市地铁3号线不良地质问题及对策研究[J]. , 2010, 31(S2): 317-321.
[15] 白 冰,李小春,石 露,唐礼忠. 弹塑性应力-应变曲线的斜率恒等式及其验证和应用[J]. , 2010, 31(12): 3789-3792.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!