Force and Deformation Characteristics of Large-Scale Zoning Excavation in Soft Soil: A Case Study in Hangzhou

Applied Sciences, Год журнала: 2024, Номер 14(14), С. 6358 - 6358

Опубликована: Июль 21, 2024

The zoning excavation method is fully employed to control the deformation of foundation pits constructed in urban soft soil areas. However, similarities and differences forces deformations between excavated by zonal those conventional still need be further explored. In this study, was monitored analyzed taking a pit ‘New World’ project Hangzhou City as research object. measured results showed that pre-built diaphragm wall for first restricted wall. presence extensive construction unloading activities also changed pattern soil. Further, finite element simulations were carried out. simulation revealed excavating caused displacements transmitted non-adjacent through small concentrated at junction two sub-pits. Adjacent large with similar displacement patterns. study can provide effective guidance areas future.

Язык: Английский

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Performance of isolation piles in protecting subway tunnels adjacent to foundation pits: Experimental and numerical investigations

Tunnelling and Underground Space Technology, Год журнала: 2024, Номер 156, С. 106221 - 106221

Опубликована: Ноя. 25, 2024

Язык: Английский

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The critical width-height ratio of finite soil behind retaining wall considering the compaction degree of fill under RB mode

Journal of Measurements in Engineering, Год журнала: 2025, Номер unknown

Опубликована: Янв. 8, 2025

The compaction degree of fill is an important index for quality control slope support engineering. Aiming at the influence factor fill, effect on characteristics active fracture surface and critical width-height ratio finite soil under RB model was investigated through laboratory test numerical simulation. primary research findings are as follows: (1) Under mode, inclined plane that does not pass heel wall, there often multiple nearly parallel planes in fractured body. semi-infinite between movable retaining wall surface, fixed wall. (2) For loose (λ= 81 %), upper point gradually moves upward from to with increase becomes steeper, changes into soil. (3) degree, but two walls still semi-infinite. (4) model, actively destroyed decreases linearly degree. After fitting, empirical equations experimental simulated values considering given respectively. (5) failure mechanism similar push slide slope, development process top-down sliding layer by layer. this paper shows affecting width height soil, it define or state behind

Язык: Английский

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Strength Prediction Model for Cohesive Soil–Rock Mixture with Rock Content

Applied Sciences, Год журнала: 2025, Номер 15(2), С. 843 - 843

Опубликована: Янв. 16, 2025

Fault fracture zones, characterized by high weathering, low strength, and a degree of fragmentation, are common adverse geological phenomena encountered in tunneling projects. This paper performed series large-scale triaxial compression tests on the cohesive soil–rock mixture (SRM) samples with dimensions 500 mm × 1000 to investigate influence rock content PBV (20, 40, 60% volume), orientation angle α, confining pressure their macro-mechanical properties. Furthermore, numerical model, which takes into account was constructed means PFC3D evolution mechanical properties SRM. The results indicated that (1) α is significant at pressures. For sample an 0°, shear failure inhibited, blocks tended break more easily, while 30° 60° exhibited fewer fragmentations. (2) significantly affected behaviors peak deviatoric stress 0° minimized lower (<20%), both deformation modulus were larger (>60%). Based these findings, equation correlating strength proposed under consistent matrix conditions. effectively predicts SRM different values.

Язык: Английский

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Observation and Analysis of Deformation Control Performance of Hydraulic Servo Steel Support for a Soft Soil Pit—A Case Study of a Pit Project in Hangzhou

Buildings, Год журнала: 2025, Номер 15(7), С. 1002 - 1002

Опубликована: Март 21, 2025

As foundation pit engineering is developing towards larger and deeper designs, the requirements for controlling excavation-induced deformation are becoming increasingly stringent, particularly in complex urban environments soft soil areas. In recent years, numerous projects have incorporated Hydraulic Servo Steel Support (HSSS) to actively manage axial forces of internal supports, which has achieved significant reductions displacement retaining structures (δD). An investigation cases areas revealed that average ratios δD excavation depth (H) pits with without servo control systems were 0.11% 0.38%, respectively. This study analyzed monitoring data related δD, outside pit, changes force supports a deep located Hangzhou City, China. The results indicated employing zoned HSSS effectively controlled δD. During stage, ensured remained below design threshold, although some persisted during dismantling stage. Additionally, adjustments affected adjacent common occurrence reverse pulling first-layer due action HSSS. Therefore, further optimization necessary enhance effectiveness.

Язык: Английский

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Seismic Non-Limited Active Earth Pressure Analysis of Retaining Walls Under Rotation-About-the-Base Mode

Applied Sciences, Год журнала: 2025, Номер 15(8), С. 4202 - 4202

Опубликована: Апрель 10, 2025

Under seismic loading conditions, the backfill soil behind retaining walls does not fully reach limit state, while earth pressure is influenced by wall displacement. The RB (rotation about base) displacement pattern represents a prevalent deformation mode in during operational service. To calculate non-limited active under mode, this study first establishes relationship between critical horizontal (corresponding to mobilized wall–soil interface friction angle) and depth based on numerical simulations, revealing linear correlation. Subsequently, nonlinear distribution relationships for internal angle with wall-top are derived. Building upon foundation considering failure mechanism of displacement, mass divided into inclined slices. A pseudo-static analytical framework proposed both magnitude application point rigid Validation against experimental data from referenced studies demonstrates method’s rationality. Earth transitions an initially concave triangular as progresses. descends initial at-rest position (1/3 H) increasing subsequently rising approaches full states, ultimately stabilizing at 1/3 H distribution. parameter sensitivity analysis section summarizes that coefficient dominates influencing factors, followed soil–wall exhibit relatively minor effects. These findings provide insights optimizing design methodologies structures.

Язык: Английский

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Performance of adjacent metro tunnels during deep excavation: A case study in Hangzhou

Transportation Geotechnics, Год журнала: 2025, Номер unknown, С. 101585 - 101585

Опубликована: Май 1, 2025

Язык: Английский

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Analysis of Offshore Pile–Soil Interaction Using Artificial Neural Network

Journal of Marine Science and Engineering, Год журнала: 2025, Номер 13(5), С. 986 - 986

Опубликована: Май 20, 2025

Offshore wind power is one of the primary forms utilizing marine green energy in China. Currently, near-shore predominantly employs monopile foundations, with designs typically being overly conservative, resulting high construction costs. Precise characterization interaction mechanisms between piles and surrounding soils crucial for foundation design optimization. Traditional p-y curve methods, simplified fitting functions, inadequately capture complex pile–soil behaviors, limiting predictive accuracy model uncertainty quantification. To address these challenges, this research collected 1852 empirical datasets offshore interactions, developing horizontal displacement prediction models using artificial neural network (ANN) expressions comprehensive statistical analysis. The constructed ANN demonstrates a simple structure satisfactory performance, achieving average error margins below 6% low to moderate dispersion (26%~45%). In contrast, traditional show 30%~50% biases substantial near 80%, while conventional finite element methods exhibit approximately 40% dispersion. By strictly characterizing probability cumulative function factors, provided reliability-based design. Through case verification, it demonstrated that ANN-based has significant advantages terms computational efficiency foundations.

Язык: Английский

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Influence of Pile Foundation Construction on Existing Tunnels in a Metro Protection Area: Field Test and Numerical Simulation

Buildings, Год журнала: 2024, Номер 14(8), С. 2280 - 2280

Опубликована: Июль 24, 2024

On the basis of Fengqi Chaoming project in Hangzhou City, Zhejiang Province, China, this paper investigates influence pile foundation construction on existing tunnels a metro protection area to ensure stability and safety Metro Line 2 through situ tests numerical simulations. The test results show that has certain tunnels, degree gradually decreases as distance between tunnel increases. corresponding impact level for at 12 m from is 1.06 mm, 4.9 1.18 mm. Different types foundations also lead different degrees influence. maximum settlement triaxial cement mixing piles 1.89 while hard-method occlusal monitoring point with smallest experiences largest deformation, but several sets deformation data meet requirements control index, indicating safe controllable.

Язык: Английский

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Impact of Excavation on Adjacent Elevated Bridges and Optimization Analysis of Deformation Control

Buildings, Год журнала: 2024, Номер 14(10), С. 3197 - 3197

Опубликована: Окт. 8, 2024

Based on the deep foundation pit project of TOD (Transit-Oriented Development) complex Shaoxing North High-speed Railway Station, influence different construction stages deformation and inclination rate adjacent elevated bridge its variation law are studied through field measurement numerical simulation. The process is optimized by method reinforcement outside adjustment preloaded axial force, distance bridges summarized. results show that with excavation pit, pier pile gradually increases, piers larger than foundations. As depth soil force maximum vertical displacement foundations decreases. deeper reinforcement, better control effect bridge. In actual construction, it recommended be taken as pit. It obvious subject to angle effect, appropriate value should selected according site conditions. generally shows a decreasing trend increase in between When close will affected fluctuation decrease. conclusions drawn article can serve basis reference for design provide similar projects.

Язык: Английский

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