Construction of a subway station in Shanghai called for 31.4–33.1–m-deep excavation, which extended through upper impermeable clayey strata into underlying erodible silt and sand aquifer layers. When the north section this pit nearly bottomed out on July 23, 2013, sudden outburst groundwater took place base was flooded quickly. In subsequent two days, adjacent ground building successively underwent 30–42-mm settlements plunging manner. To prevent aggravation situation, contingency plan...

From 2005 to 2010, a large excavation (approximately 26,000 m2 in plane) was conducted stiff clay deposits for the Gate of Orient building Suzhou, China. To reduce project cost and shorten construction duration, composite earth-retaining systems were designed this excavation, i.e., removal uppermost 7.85 m soil mostly by sloped open-cut method, leaving one side supported nailing wall (SNW); subsequent depth 21.5 retained multipropped continuous bored pile (CBP) wall; final two inner pits...

This paper introduces thirteen kinds of typical excavation failures widely encountered in practice China along with corresponding failure mechanisms and damages to adjacent structures facilities. Emphasis is placed on investigation longitudinal slip during subway station, which frequently occurs but rarely receives serious attention. based a sliding event Hangzhou, China, soft earthen slope about 13 m high inside an uncompleted station underwent massive failure. Slide debris travelling...

The failure of Shanghai Metro Line 4 in 2003 was one the most striking accidents history subway construction China. It involved first breach a cross passage being mined by an artificial ground-freezing method, followed massive ingress water and soil, dramatic ground subsidence, rapid sinking existing structures, adjacent dike floodwall along Huang-Pu River, flooding site, collapse buildings metro tunnels. accident directly resulted from excavated within confined aquifer. In beginning,...

Because of its great length, one subway terminal excavation in Shanghai, China, was divided into two pits for sequential construction. Although it featured an adequate earth-supporting system and the field construction followed proper procedure, wall ground displacements first excavated pit were up to 1.8–2.7 times local specifications. Then, basal strata second jet grouted. Unfortunately, worse performance tracked. Technical review design plans, logs, data, postconstruction investigations...

This paper presents the results of statistical analyses on a database comprising 592 deep excavations in Shanghai soft clays from 1995 to 2018. First, general trends and patterns over time are outlined for seven different excavation methods types earth-supporting systems. Then, major design factors characterized manner. Based collected data, frequency distributions δhm/He data (δhm = maximum lateral wall displacement; He final depth) corresponding each method system presented; furthermore,...

Abstract Industrial data trading can considerably enhance the economic and social value of abundant resources. However, traditional models are plagued by critical flaws in fairness, security, privacy regulation. To tackle above issues, we first proposed a distributed industrial architecture based on blockchain cloud for multiple owners. Subsequently, realized implemented identity management verifiable credentials scheme that possesses desirable properties, i.e., selective disclosure,...

Any deficiency in excavation design or construction could lead to excessively large retaining wall and ground displacements, usually accompanied by damage adjacent structures facilities. This paper documents a case history of small air shaft Shanghai soft clay. Its maximum lateral displacement settlement were twice three times the local deformation control criteria 3 14 those one featuring similar subsurface conditions, geometric size, supporting system. To identify probable causes...

The stems of Dendrobium officinale Kimura et Migo (Dendrobii Officinalis Caulis) have a high medicinal value as traditional Chinese medicine (TCM). Because the limited supply, D. is priced TCM, and therefore adulterants are commonly found in herbal market. dried closely related species, devonianum Paxt., used substitute; however, there no effective method to distinguish two species. Here, performance liquid chromatography (HPLC) was successfully developed applied differentiate by comparing...

Analyses of well-documented field instrumentation data from two deep excavations in Shanghai soft ground indicate that displacements shallowly buried pipelines caused by adjacent excavation are predominantly governed the locations relative to pits and much less affected pipeline flexural rigidity or soil bedding stiffness. On average, circular produce smaller settlement (uy<0.16%He) than do rectangular (uy≤0.42–0.46%He), where uy He denote final depth, respectively. Despite this discrepancy,...

To date, why a 13-story building in Shanghai fell abruptly to the ground 2009 remains uncertain. By review of physical evidence, limit-equilibrium analyses, extensive calculations, and three-dimensional numerical simulations, this study reveals that failure arose from rainfall-triggered undrained general shear subgrade underneath adjacent stockpile rather than previously identified lateral movement shearing off piles below or along excavation side incurring progressive tilting building....

Abstract Numerous users are experiencing unsafe communications due to the growth of big network mediums, where no node communication is detected in emergency scenarios. Many people find it difficult communicate situations as a result such communications. In this paper, mobile cloud computing procedure implemented suggested technique order prevent circumstances, and make data transmission process more effective. An analytical framework that addresses five significant minimization maximization...

The destructive failure of Shanghai Metro line 4 across underneath the Huangpu River on July 1, 2003, led to massive ground subsidence and collapse pre-existing structures in proximity; additionally, generated large amounts human-made rigid obstructions strata, which made rehabilitation collapsed metro be very technically challenging. By extensive comparisons terms technical difficulties, economic costs, construction durations, a plan reconstruction at its original location rather than...

The mechanical behaviors of gravelly sands are greatly affected by the morphology and size gravel grains. In this paper, a systematic approach that integrated computational geometry was proposed to simulate grains with different angularity aspect ratio in discrete element method (DEM) modeling. A random circumscribed polygon first created, disks sizes were laid along medial axes polygon. This medial-axis-oriented disk-laying very efficient regard high area coverage rate achieved number...

Using large-scale atomic/molecular massively parallel simulator (LAMMPS), we have studied the liquid behaviors of Cu61.8Zr38.2, Cu64.5Zr35.5, and Cu66Zr34 amorphous alloys including their pair distribution functions, distributions Voronoi clusters with different coordination numbers, mean square displacements Cu Zr atoms. Compared to Cu61.8Zr38.2 Cu66Zr34, found high concentrations distorted icosahedra indices ⟨0,2,8,2⟩ ⟨0,4,4,4⟩, numbers Cu-centered Cu8Zr5 Cu9Zr4 clusters, reduced atomic...