Reliability Analysis for Serviceability Limit State of Pile Groups Foundation

Xiao-ya Bian,Jun-jie Zheng,Rong-Jun Zhang,Zhi-jun Xu 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1

The aim of this paper is to present an approach for the assessment of the Serviceability Limit State (SLS) reliability of pile groups foundation combining the Ultimate Limit State (ULS) reliability method of pile groups. To this end, the linear relationship between the ULS and SLS reliability indices is presented using the formulas for calculating the ULS and SLS reliability indices of single piles. Meanwhile, the influence of system effects, correlation coefficient between pile group efficiency and system effects (ρζ,χ), and limiting tolerable settlement (Slt) on the SLS reliability analysis of pile groups foundation is studied using pile load test data compiled for illustration. The results indicate that both the ULS reliability index (βG-uls) and the SLS reliability index (βG-sls) of pile groups foundation decrease with ρζ,χ, that powerful system effects can enhance the ULS and SLS reliability of pile groups foundation, and that βG-sls increases with Slt. the reliability level estimated by pile load test data is equivalent to that incorporating the SLS requirements with a certain value of Slt between 15 mm and 25 mm. For Slt larger than this value, Reliability-based Design (RBD) of pile groups foundation will depend on the ULS requirements, but, conversely, RBD will depend on the SLS requirements.

Incorporating Serviceability Limit State Requirements into Reliability-based Analysis and Design of Piles

Xiao-ya Bian,Jun-jie Zheng,Zhi-jun Xu 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.4

This study develops a novel reliability-based approach for the analysis and design of piles by incorporating Serviceability Limit State (SLS) requirements into Load and Resistance Factor Design (LRFD) for Ultimate Limit States (ULS). Three methods for reliability-based analysis and design, namely the Mean Value First Order Second Moment (MVFOSM) method, the Advanced First Order Second Moment (AFOSM) method, and the Monte Carlo Simulation (MCS) method, are employed for comparison. In order to expediently quantify model uncertainties for SLS and incorporate them into the process of reliability-based analysis and design of piles, the SLS model factor (or bias factor) is established based on a two-parameter, hyperbolic curve-fitting equation describing the load-settlement relation. Herein, the limiting tolerable foundation settlement (slt) is treated as a random variable. Four load test databases from South Africa presented by Dithinde et al. (2011) are compiled again to conduct reliability analysis and calculate resistance factors. The case studies illustrate that the AFOSM method has the higher accuracy than the MVFOSM method as verified using the MCS method. This study recommends the AFOSM method to perform reliability analysis and determine resistance factors for Reliability-Based Design (RBD).

Mapping the Most Massive Overdensities through Hydrogen (MAMMOTH). II. Discovery of the Extremely Massive Overdensity BOSS1441 at<i>z</i>= 2.32

Cai, Zheng,Fan, Xiaohui,Bian, Fuyan,Zabludoff, Ann,Yang, Yujin,Prochaska, J. Xavier,McGreer, Ian,Zheng, Zhen-Ya,Kashikawa, Nobunari,Wang, Ran,Frye, Brenda,Green, Richard,Jiang, Linhua American Astronomical Society 2017 The Astrophysical journal Vol.839 No.2

<P>Cosmological simulations suggest a strong correlation between high optical-depth Lya absorbers, which arise from the intergalactic medium, and 3D mass overdensities on scales of 10-30 h(-1) comoving Mpc. By examining the absorption spectra of similar to 80,000 QSO sight lines over a volume of 0.1 Gpc(3) in the Sloan Digital Sky Survey III (SDSS-III), we have identified an extreme overdensity, BOSS1441, which contains a rare group of strong Lya absorbers at z = 2.32 +/- 0.02. This absorber group is associated with six QSOs at the same redshift on a 30 comoving Mpc scale. Using Mayall/MOSAIC narrowband and broadband imaging, we detect Lya emitters (LAEs) down to 0.7 x L-Ly alpha ' * a and reveal a large-scale structure of LAEs in this field. Our follow-up LBT observations have spectroscopically confirmed 20 galaxies in the density peak. We show that BOSS1441 has an LAE overdensity of 10.8 +/- 2.6 on a 15 comoving Mpc scale, which could collapse to a massive cluster with M greater than or similar to 10(15) M-circle dot at z similar to 0. This overdensity is among the most massive large-scale structures at z similar to 2 discovered to date.</P>

Discovery of an Enormous Ly<i>α</i>Nebula in a Massive Galaxy Overdensity at<i>z</i>= 2.3

Cai, Zheng,Fan, Xiaohui,Yang, Yujin,Bian, Fuyan,Prochaska, J. Xavier,Zabludoff, Ann,McGreer, Ian,Zheng, Zhen-Ya,Green, Richard,Cantalupo, Sebastiano,Frye, Brenda,Hamden, Erika,Jiang, Linhua,Kashikawa, American Astronomical Society 2017 The Astrophysical journal Vol.837 No.1

<P>Enormous Ly alpha nebulae (ELANe), unique tracers of galaxy density peaks, are predicted to lie at the nodes and intersections of cosmic filamentary structures. Previous successful searches for ELANe have focused on wide-field narrowband surveys or have targeted known sources such as ultraluminous quasi-stellar objects (QSOs) or radio galaxies. Utilizing groups of coherently strong Ly alpha absorptions, we have developed a new method to identify high-redshift galaxy overdensities and have identified an extremely massive overdensity, BOSS1441, at z = 2-3. In its density peak, we discover an ELAN that is associated with a relatively faint continuum. To date, this object has the highest diffuse Ly alpha nebular luminosity of L-nebula = 5.1 +/- 0.1 x 10(44) erg s(-1). Above the 2 sigma surface brightness limit of SBLy alpha = 4.8 x 10(-18) erg s(-1) cm(-2) arcsec(-2), this nebula has an end-to-end spatial extent of 442 kpc. This radio-quiet source also has extended C IV lambda 1549 and He II lambda 1640 emission on greater than or similar to 30 kpc scales. Note that the Ly alpha, He II, and C IV emissions all have double-peaked line profiles. Each velocity component has an FWHM of approximate to 700-1000 km s(-1). We argue that this Lya nebula could be powered by shocks due to an active galactic nucleus-driven outflow or photoionization by a strongly obscured source.</P>

Cloning and functional characterization of two GsSnRK1 gene promoters from wild soybean

Chen Jun,Li Qiang,Zhang Pengmin,Lu Haoran,Bian Ya,Jian Yi,Wang Yizhu,Ding Xiaodong,Xiao Jialei 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.5

Sucrose non-fermenting-related protein kinase 1 (SnRK1) belongs to a plant serine/threonine protein kinase family, and is part of a large interactive network of signaling pathways in plants to regulate many aspects of growth and development, and its gene expressions are highly responsive to multiple external stimuli. To functionally characterize the role of different SnRK1 members in wild soybean and identify the expression patterns of novel SnRK1 promoters for transgenic research, in this study, we performed an in silico analysis of the SnRK1 gene family in wild soybean and found GsSnRK1.1 and GsSnRK1.2 are main SnRK1 isoforms in wild soybean. The promoter fragments of both GsSnRK1.1 and GsSnRK1.2 were isolated, and a series of 5′-deletion and the full-length versions of both GsSnRK1.1 and GsSnRK1.2 promoters were fused with GUS reporter gene to generate expression vectors. The GUS activities in different tissues of seedling and adult growth stages of transgenic Arabidopsis plants were determined, and the GUS activities in transgenic Arabidopsis plants under NaCl, NaHCO3, PEG, ABA, MeJA and SA were also analyzed. The results showed that GsSnRK1.1 and GsSnRK1.2 genes have different expression patterns and both promoters may contain enhancers and silencers. In addition, NaCl, NaHCO3, ABA, MeJA, and PEG treatments enhanced, whereas SA treatment decreased the GUS activity under the control of both GsSnRK1.1 and GsSnRK1.2 promoters, which may be due to the distributions of various cis-elements in both GsSnRK1.1 and GsSnRK1.2 promoter regions. These results will contribute to a better understanding of the underlying mechanisms of GsSnRK1 genes in response to various abiotic stresses, and as stress-inducible promoters, GsSnRK1.1 and GsSnRK1.2 promoters can be candidates for practical application in agriculture.