The horizontal displacement of the diaphragm wall during the excavation of the foundation pit is an important indicator of its stability. The internal force distribution and structural deformation of diaphragm walls during the excavation of foundation pits is investigated in this paper. Taking a foundation pit project in Beijing as an example, the deformation of the diaphragm wall during the excavation process is monitored using ultra-weak fiber optic grating technology and numerical simulated through the Comsol Multiphysics finite element software. The results show that ultra-weak fiber grating technology can accurately monitor minute deformations of diaphragm walls, revealing the piecewise variation of strain along depth. The location of the anchor bolts has a significant impact on the vertical distribution of deformation of the diaphragm wall, and will change the shape of the displacement curve. In this case, the strain of the second and third anchor bolts is approximately zero, which corresponds to changes in the concavity and convexity of the displacement curve.
OU Wei, CAO Ding-feng, LIU Yu-hong, WANG Hong-xian, GUO Cheng-chao, WANG Chun-yan.
Deformation of Foundation Pit Excavation Based on Ultra-weak Fiber Grating Technology[J].
Science Technology and Engineering, 2026, 26(3): 1205-1212 DOI:10.12404/j.issn.1671-1815.2501743
WangFuqiang, YuBin. Research and application of horizontal displacement monitoring algorithm based on virtual center point[J]. Yangtze River, 2023, 54(11): 214-220.
[3]
PeiH, ZhangF, ZhuH, et al. Development of a distributed three-dimensional inclinometer based on OFDR technology and the Frenet-Serret equations[J]. Measurement, 2023, 223: 113769.
SuiTengfei, HuangJianwei, YuMin. Research on high precision deformation monitoring technology of foundation pit based on close-range photogrammetry[J]. Journal of Hefei University of Technology (Natural Science Edition), 2023, 46(6): 828-832.
[6]
WuJ, PengL, LiJ, et al. Rapid safety monitoring and analysis of foundation pit construction using unmanned aerial vehicle images[J]. Automation in Construction, 2021, 128: 103706.
DaiZhihong, LuPeng, ZhangZhifang, et al. Surface subsidence monitoring and analysis of Nanning based on PS-InSAR technology[J]. Journal of Geodesy and Geodynamics, 2021, 41(5): 491-496, 519.
LiWenjie, ZhaoJie. Analysis of deformation properties of internally supported deep excavation based on HSS model and distributed optical fiber monitoring[J]. Science Technology and Engineering, 2023, 23(18): 7913-7923.
ChenBo. Research on the application of multi-monitoring technology in underground rail transit engineering[J]. Surveying and Mapping Bulletin, 2024 (S2): 115-121.
ZhengXuezha, SuHaijiao, TongXin, et al. Review of InSAR surface deformation monitoring technology for coal mine areas[J]. Bulletin of Surveying and Mapping, 2025(2): 64-70.
WangNansu, HongChengyu, LiuWenli, et al. Research on mechanical properties of underground pit support based on distributed optical fibre sensing technology[J]. Modern Tunneling Technology, 2020, 57(S1): 877-883.
LuYi, SongZezhuo, LiuJin, et al. Land subsidence monitoring and deformation analysis of Tongzhou Bay Area based on DFOS[J]. Journal of Hehai University(Natural Science Edition), 2023, 51(2): 81-88.
SunBinyang, ZhangPingsong. Research progress and prospect of surrounding rock deformation and failure monitoring in stope based on DFOS[J]. Journal of Engineering Geology, 2021, 29(4): 985-1001.
TangJixin, WangQunmin, ChenWenhua, et al. Application of fiber bragg grating sensing and photoelectric imaging technology in deep metro foundation pit[J]. Tunnel Construction, 2019, 39(S1): 361-368.
WangJin, SunChao, FuQiao, et al. Deformation monitoring technology of underground diaphragm wall based on brillouin optical frequency domain analysis[J]. Tunnel Construction, 2021, 41(S2): 558-564.
HuYang, GuoTongda, LongWanxue, et al. Research on deformation characteristics and internal forces of double-row circular piles based on BOTDA distributed optical fiber sensing technology[J]. Journal of Xi’an University of Architecture and Technology(Natural Science Edition), 2021, 53(5): 692-699.
LiuJie, ShiBin, ZhangDan, et al. Experimental study of foundation pit monitoring using BOTDR-based on distributed optical fiber sensor[J]. Geotechnics, 2006(7): 1224-1228.
CaoJianxin. Bridge structure deformation monitoring method based on ultra-weak fiber bragg grating array and its application[J]. World Bridge, 2025, 53(1): 102-107.
JiangWeile, YaoKun, LinQijing, et al. Application of structural health monitoring system in wooden-structure ancient buildings[J]. Journal of Sensing Technology, 2024, 37(8): 1295-1306.
[39]
HanH, ShiB, ZhangL, et al. Deep displacement monitoring and foundation base boundary reconstruction analysis of diaphragm wall based on ultra-weak FBG[J]. Tunnelling and Underground Space Technology, 2021, 117: 104158.
GuoBin, LiuYongli, ZhouWenzuo, et al. Study of brillouin optical time-domain reflectometer applied to model experimental test[J]. Science Technology and Engineering, 2021, 21(4): 1422-1428.
[42]
YeX, ZhuH H, WangJ, et al. Subsurface multi-physical monitoring of a reservoir landslide with the fiber-optic nerve system[J]. Geophysical Research Letters, 2022, 49(11): e98211.
[43]
HanH M, ShiB, ZhangC C, et al. Application of ultra-weak FBG technology in real-time monitoring of landslide shear displacement[J]. Acta Geotechnica, 2023, 18(5): 2585-2601.
[44]
HanH, ShiB, YangY, et al. Ultra-weak FBG sensing for identification and analysis of plastic zone of soil caused by supported excavation[J]. Engineering Geology, 2023, 317: 107061.
LuoZhihui, WangXiaolong, LiangYonghui, et al. Migration monitoring method for ancient building based on ultra-weak fiber bragg grating[J]. Laser & Optoelectronics Progress, 2025, 62(3): 126-133.
TongGuangqin, LiuDingming, ChenZihan, et al. Research on fiber-optic flexible slope measurement system for landslide based on ultra-weak fiber grating[J]. China Rural Water Conservancy and Hydropower, 2025(7): 177-181.
YiShun, ChenJian, PanJiajun, et al. Study on characterization function of horizontal deformation for retaining wall of braced excavation[J]. Geotechnics, 2024, 45 (S1): 568-578.
LiJilin, YinAiyue, WeiHuanwei, et al. Study on influence of excavation width on deformation of supporting structure in L-shaped corner area of shaped foundation pit[J]. Journal of Building Science and Engineering, 2024, 41(4): 159-170.