Abstract
Most of the hydraulic structures in Korea were built before 1970, with 69.4% of them having a service life exceeding
50 years. Ordinary Portland cement (OPC), which is currently in general use for the construction of these structures, is
continuously facing price increases. In addition, considerable amounts of greenhouse gases generated during the manufacturing
process cause environmental problems. Therefore, in this study, ZA-SOIL, a material developed by recycling inexpensive blast
furnace slag powder and desulfurized gypsum, was mixed with sodium silicate and silica sol in a liquid state and evaluated as an
alternative to OPC. The compressive strength and environmental characteristics of the ZA-SOIL product were experimentally
compared with those of OPC to evaluate its applicability as a grout material. The results indicated that the compressive strength
of the developed ZA-SOIL was 3.23, 2.88, and 1.25 times higher than that of OPC after 3, 7, and 28 d of curing, respectively. In
addition, ZA-SOIL satisfied all prescribed criteria and was found to be environmentally stable. Further evaluation of the field
applicability of ZA-SOIL revealed that the electrical resistivity increased after reinforcement, depending on the depth, and the
permeability coefficient (k) sharply decreased. Therefore, ZA-SOIL, developed by recycling inexpensive circulated resources,
shows potential as an OPC substitute.
Address
Semin Kim: Department of Civil Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea
Suhyun Park: Department of Research Institution, ZIAN Co. Ltd., Wangu 55338, Republic of Korea
Kangsoo Lee: DL E&C, 36, Seoul-si 03152, Republic of Korea
Dae-sung Cho: Technical Development Department, N-Genius Co., Ltd., Anseong 17508, Republic of Korea
Abstract
Tunnel structures that pass through active faults are prone to serious damage under the action of fault displacement.
When the tunnel cannot avoid active faults, a series of disaster reduction measures need to be taken to reduce the impact of fault
displacement on the tunnel. In current work, firstly, a three-dimensional numerical analysis model was established, and the
numerical model was validated through existing centrifugal model experiments. Then, by comparing the damage response of
articulated tunnels and integral tunnels under fault action, the energy dissipation mechanism and disaster reduction effect of
articulated design method were researched, and the key parameters in the articulated design method, such as the longitudinal
position, elastic modulus and length of flexible joint and the length of lining segment, were further analyzed for their influence
on the disaster reduction effect. Finally, considering the possibility of groundwater seepage during tunnel operation in areas with
abundant water, a variable cross-section disaster reduction method based on the articulated design was proposed, and the disaster
reduction effect under different parameter influences were discussed. This work can provide meaningful references for the
disaster reduction design method of sand tunnels under the action of bedrock normal fault dislocation.
Key Words
articulation design; bedrock normal fault dislocation; disaster reduction effect; sandy tunnel; variable crosssection
Address
Yu Zhang and Shuyuan Xie: School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
Shao An, Lianjin Tao and Xu Zhao: The Key Laboratory of Urban Security and Disaster Engineering, Ministry of Education,
Beijing University of Technology, Beijing, China
Qiang Zhang: Beijing Maintenance Group Co., Ltd, Beijing, China
Abstract
In this study, a design method using system stiffness influence factor (IF) was established to characterize the
excavation-induced wall and ground movements with changes in groundwater level (GWL). The established factor for
quantifying wall and ground behavior in this study considering GWL was regarded as an important aspect to prevent failures and
ensure stable support systems design for the target structure. Irregular excavation configuration, common in urban areas, was
considered using the three-dimensional finite element (FE) analysis, as well as different GWLs and various influence parameters
for wall and support systems. Wall deflection and surface settlement were shown to decrease as the groundwater level was
lowered and system stiffness was increased, especially with larger wall bending stiffness, higher wall embedment depth, and
reduced vertical and horizontal strut spacings. These effects were particularly noted within re-entrant corner zones due to the
corner stiffening effect. The influence of individual parameters was evaluated and quantified using the IF. A modification
procedure for the IF was introduced to incorporate the effects of groundwater level, and the proposed method was shown to
effectively predict wall deflection and ground settlement. Case example data confirmed the validity of this method, and its
applicability in enhancing and optimizing excavation design was demonstrated. Overall, the proposed approach was offered as a
practical and innovative framework for the design of excavation support systems under the influence of groundwater.
Key Words
finite element analysis; excavation; ground settlement; groundwater level; support system; wall deflection
Address
Qaisar Abbas: Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum and Minerals,
31261, Dhahran, Saudi Arabia
Jonghyeog Yoon, Donggun Nam, Jiyeong Lee and Junhwan Lee: School of Civil and Environmental Engineering, Yonsei University, 50, Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
Abstract
The shape of natural rock and soil particles is distinct and their orientation may prefer a certain direction, and
determining the influences of particle shape and initial particle orientation on dry and immersed granular collapse is of great
significance to prevention of geological disasters such as subaerial and submarine landslides. Using the superquadric DEM and
the coupled CFD-DEM, the dry and immersed collapse process of granular columns with different particle shapes (aspect ratio A
and blockiness B) and different initial particle orientations o are simulated. The results show that, compared with the case of A =
1 (spherical), the collapse of particles with larger A (elongated) or smaller A (platy) results in a shorter final runout distance and a
higher final deposit height. The collapse of particles with larger B (more angular) also results in a shorter final runout distance
and a higher final deposit height. The collapse of particles with o = 0 (approximately horizontal) produces an obviously smaller
final runout distance, and progresses in a particular way that some particles being first squeezed out from the lateral free surface
followed by the gradual slide of particles in the upper parts. For platy ellipsoidal particles, the collapse of particles with o = 135
(leaning on the fixed wall) generates the longest final runout distance. Whereas, for elongated ellipsoidal particles, the collapse
of particles with o = 90 (approximately upright) generates the longest final runout distance.
Address
Lei Jin and Jingjing Li: College of Civil Engineering, Jiangsu Open University, Jiangsu, China
Wenjie Xu: State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, China
Abstract
Biopolymer-based soil treatment (BPST) has recently been introduced as a new ground improvement method for
environmentally friendly and sustainable development. Numbers of research have investigated BPST effects on the soil
hydraulic conductivity, while there are lack of studies considering in-situ stress (i.e. vertical confinement and groundwater
pressure) conditions. In this study, the effect of gellan gum BPST on the hydraulic conductivity behavior of sands was assessed
using a pressurized permeability test apparatus which allows separate vertical confinement and pore pressure control. The
hydraulic conductivity of gellan gum biopolymer-treated sands were measured with different biopolymer contents, vertical
confinement levels, and pore water pressure conditions. Laboratory test results show that the hydraulic conductivity of gellan
gum-treated sands attribute to 1) biopolymer-particle bonding, 2) biopolymer hydrogel induced pore-clogging, and 3) hydrogel
alteration due to pore pressure increase, where gellan gum BPST is postulated to be an effective manner for ground hydraulic
conductivity control in geotechnical engineering practice.
Key Words
effective stress; gellan gum; hydraulic conductivity; pore-clogging; water pressure
Address
Thi-Phuong-An Tran and Tran Thanh Nhan: Department of Hydrogeological and Geotechnical Engineering, University of Sciences, Hue University, 77 Nguyen Hue, Vietnam
Ilhan Chang: Department of Civil Systems Engineering, Ajou University, Suwon 16499, Korea
Minhyeong Lee: Disposal Performance Demonstration Research Division, Korea Atomic Energy Research Institute (KAERI),
Daejeon 34057, Republic of Korea
Gye-Chun Cho: Department of Civil Engineering, Korean Advanced Institute for Science and Technology,
291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
Abstract
This study proposed a new "grouting-soil-pier interaction transmission model", using work done on soil per linear
meter to reflect the impact of soil displacement on the bridge pier. Exploring the relationship between grouting volume, soil
displacement, and bridge pier displacement, the relationship between bridge pier horizontal displacement and grouting volume is
divided into three zones: linear, nonlinear, and ineffective. A continuous transition from linear to nonlinear behavior is
formulated, thereby elucidating the entire progression of pier displacement. For the present project, In the range of grouting
distance [0, 5] meters and volume [0, 120] cubic meters, a proportional relationship is observed. Field tests show that the error
between derived and measured slopes of pier displacement is under 10%, validating the model. Further exploration reveals that
the maximum bending moment and maximum soil displacement occur at the same depth, which corresponds to the silt layer.
Under different pile deflection conditions, the ratio of work done on soil per linear meter to pile strain energy varies, indicating
different energy transfer efficiencies.
Address
Zhijie Peng, Tingjin Liu, Liangyi Cai, Huashan Zhong and Jitao Jia: School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, Guangdong, China
