Hao Didi, Miao Changqing, Fang Shisheng, Wang Xudong, Shu Qiaoqiao
Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing 211189, China.
School of Civil Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2024 Sep 21;17(18):4642. doi: 10.3390/ma17184642.
To study the performance of lightweight foamed concrete (LWFC) in widened embankments of high-speed railways, this study first conducted numerous strength, permeability, and water immersion tests to investigate the mechanical properties and water resistance of LWFC with designed dry densities of 550, 600, and 650 kg/m. Secondly, a field test was performed to analyze the behavior of the deformation and the internal pressure within the LWFC-filled portions. Furthermore, a parametric study via numerical modeling was performed to investigate the effects of four key factors on the performance of the LWFC-filled, widened embankments. Results showed that LWFC possesses adequate bearing capacity and impermeability to meet high-speed railway embankment widening requirements. However, water seepage reduces LWFC strength. The additional pressure from LWFC filling increases initially but then decreases once dehydration occurs. The settlement induced by LWFC accounted for 71% of the total filling height, which is only 37.5% of the total settlement after construction. The parametric study results show that the maximum settlement of widened and existing portions induced by LWFC was 46.3-49.6% and 48.3-53.2% of those induced by traditional fillers due to the LWFC's lower density as well as their better self-supporting ability. Making an appropriate reduction in the thickness of the retain wall installed against the LWFC-filled widened embankment of the high-speed railway generates a few variations in the lateral deformation of the wall. Furthermore, the effects of the pile offset on the deformation of the LWFC-filled embankment were more sensitive compared to the diameter of the piles.
为研究轻质泡沫混凝土（LWFC）在高速铁路加宽路堤中的性能，本研究首先进行了大量强度、渗透性和浸水试验，以研究设计干密度为550、600和650kg/m的LWFC的力学性能和耐水性。其次，进行了现场试验，以分析LWFC填充部分的变形行为和内部压力。此外，通过数值模拟进行了参数研究，以研究四个关键因素对LWFC填充加宽路堤性能的影响。结果表明，LWFC具有足够的承载能力和抗渗性，能够满足高速铁路路堤加宽的要求。然而，渗水会降低LWFC强度。LWFC填充产生的附加压力最初会增加，但一旦发生脱水就会减小。LWFC引起的沉降占总填充高度的71%，仅为施工后总沉降的37.5%。参数研究结果表明，由于LWFC密度较低且自支撑能力较好，LWFC引起的加宽部分和现有部分的最大沉降分别为传统填料引起的最大沉降的46.3 - 49.6%和48.3 - 53.2%。适当减小安装在高速铁路LWFC填充加宽路堤一侧的挡土墙厚度会使墙体横向变形产生一些变化。此外，与桩径相比，桩偏移对LWFC填充路堤变形的影响更敏感。
