Learning of Soil Behavior from Measured Response of a Full Scale Test Wall in Sandy Soil

In urban deep excavations, instruments are placed to monitor deformations and to control construction and reduce the risk of excessive and potentially damaging deformations. The second author has introduced a new inverse analysis approach that utilizes measured excavation performance to extract the underlying soil behavior. The extracted soil behavior can be used in predicting the behavior of similar excavations. This paper provides a first implementation of this inverse analysis approach to a well instrumented full scale test wall in a sand deposit. A wall consisting of soldier beams with wood lagging was instrumented to study anchored (one and two level tie backs) wall behavior in sandy soil deposits at Texas A&M. Strain gauges, load cells, inclinometers, and settlement points were placed in two sections of the excavation to monitor the excavation behavior. The measured excavation response for the section with two-level tie-backs is used to extract the constitutive model through the inverse analyses approach. The extracted constitutive model is used in predicting the underlying soil behavior for the section with one tie-back level. The predicted behavior of the excavation and its agreement with measurements at the site are discussed in detail

Non-Linear Site Response Analysis for Deep Deposits in the New Madrid Seismic Zone

The New Madrid Seismic Zone, the most seismically active zone in the Eastern US, is overlain by deep unconsolidated deposits of the Mississippi Embayment. The deposits range in thickness from about 20 m in the St. Louis area to about 1 km in the Memphis Area and consist of silts, clays and sands. The influence of these deposits on the propagation of seismic waves to the ground surface remains a major source of uncertainty. A new non-linear one-dimensional site response analysis model is introduced for the vertical propagation of horizontal shear waves in deep soil deposits. The model accounts for the effect of large confining pressures on the strain dependent modulus degradation and damping of the soil. The capability of the new model is illustrated using soil columns at three typical locations within the Mississippi Embayment including a 1000 m column representative of conditions in Memphis. The analyses show that high frequency components usually filtered using conventional wave propagation methods, are preserved. The analyses show that spectral amplification factors for the deep deposits in the period range of 0.6-5sec range between 2 and 6, and at longer long periods (up to 10 set) can be as high as 8

Understanding the physics of kappa (κ): Insights from a downhole array

At high frequencies, the acceleration spectral amplitude decreases rapidly; this has been modelled with the spectral decay factor κ. Its site component, κ0, is used widely today in ground motion prediction and simulation, and numerous approaches have been proposed to compute it. In this study, we estimate κ for the EUROSEISTEST valley, a geologically complex and seismically active region with a permanent strong motion array consisting of 14 surface and 6 downhole stations. Site conditions range from soft sediments to hard rock. First, we use the classical approach to separate local and regional attenuation and measure κ0. Second, we take advantage of the existing knowledge of the geological profile and material properties to examine the correlation of κ0 with different site characterization parameters. κ0 correlates well with Vs30, as expected, indicating a strong effect from the geological structure in the upper 30 m. But it correlates equally well with the resonant frequency and depth-to-bedrock of the stations, which indicates strong effects from the entire sedimentary column, down to 400 m. Third, we use our results to improve our physical understanding of κ0. We propose a conceptual model of κ0 with Vs, comprising two new notions. On the one hand, and contrary to existing correlations, we observe that κ0 stabilizes for high Vs values. This may indicate the existence of regional values for hard rock κ0. If so, we propose that borehole measurements (almost never used up to now for κ0) may be useful in determining these values. On the other hand, we find that material damping, as expressed through travel times, may not suffice to account for the total κ0 measured at the surface. We propose that, apart from material damping, additional site attenuation may be caused by scattering from small-scale variability in the profile. If this is so, then geotechnical damping measurements may not suffice to infer the overall crustal attenuation under a site; but starting with a regional value (possibly from a borehole) and adding damping, we might define a lower bound for site-specific κ0. More precise estimates would necessitate seismological site instrumentation

Regioselective Green Synthesis and Antimicrobial properties of full fused non mixed Heterocyclic Systems

One pot synthesis and reaction of triazinthione and triazinohydrazide derivatives with different electrophilic reagents in ordered to synthesis of some interesting non-mixed heterocyclic compounds. Structures of thiazolotriazine, triazolotriazine, pyrimidinyltriazine, and triazinotriazine derivatives were established via spectroscopic data and elemental analysis. The synthesized compounds were screened for their antimicrobial activity

Ultrasonic and solvent free Synthesis of Regioselective Diastereomeric Adducts and Heterocyclic Products as antibacterial agent

Oxirane ring containing the carboxylic group in the α,β-position are useful intermediates in the synthesis of biologically active compounds. Epoxidation of 4-(4-acetylamino and/or bromophenyl)-4-oxo-but-2-enoic acids via ultrasound condition afforded α-oxirane carboxylic acid followed by regioselective diastereomeric adducts of camphor. The steric factor plays an important role in regioselectivity. Formation of oxirane and furan derivatives via ultrasonic condition was considered as key steps for synthesis of some important heterocyclic compounds. The structure of new synthesized compounds 2-9a,b were elucidated by elemental analysis and spectroscopic data. The antibacterial activity for the synthesized compounds was evaluated

Synthesis of bioactive quinazolin-4(3H)-one derivatives via microwave activation tailored by phase-transfer catalysis

A series of nine new 2,3-disubstituted 4(3H)-quinazolin-4-one derivatives was furnished starting from the 2-propyl-4(3H)-quinazoline-4-one (2). The reinvestigation of the key starting quinazolinone 2 was performed under microwave irradiation (MW) and solvent-free conditions. Combination of MW and phase-transfer catalysis using tetrabutylammonium benzoate (TBAB) as a novel neutral ionic catalyst was used for carrying out N-alkylation and condensation reactions of compound 2 as a simple, efficient and eco-friendly technique. The structure of the synthesized compounds was elucidated using different spectral and chemical analyses. In vitro antimicrobial activity of the compounds was investigated against four bacterial and two fungal strains; very modest activity was achieved. Some of the synthesized compounds were screened for their antitumor activity against different human tumor cell lines. The screened compounds exhibited a significant antitumor activity on some of the cancer cell lines, melanoma (SK-MEL-2), ovarian cancer (IGROV1), renal cancer (TK-10), prostate cancer (PC-3), breast cancer (MCF7) and colon cancer (HT29). The most active, even more active than the reference 5-fluorouracil, were found to be ethyl 4-[(4-oxo-2-propylquinazolin-3(4H)-yl)methyl]benzoate (3c), 3-{2-[6-(pyrrolidin-1-yl-sulfonyl)-1,2,3,4-tetrahydroquinoline]-2-oxoethyl}-2-propylquinazolin-4(3H)-one (3e), N’-[(E)-(2H-1,3-benzodioxo-5-yl)methylidene]-2-(4-oxo-2-propylquinazolin-3(4H)-yl)acetohydrazide (10a), N’-[(E)-(4-hydroxyphenyl)methylidene]-2-(4-oxo-2-propylquinazo-lin-3(4H)-yl)acetohydrazide (10b) and N’-[(E)-(4-nitrophenyl)methylidene]-2-(4-oxo-2-propylquinazolin-3(4H)-yl)acetohydrazide (10c)

Novel synthesis, ring transformation and anticancer activity of 1,3-thiazine, pyrimidine and triazolo[1,5-a]pyrimidine derivatives

Synthesis, heterocyclization and anticancer activity of a new series of heterocyclic compounds are described. Aminothiazine 1 was obtained from the base induced condensation of thiourea, benzaldehyde and ethyl cyanoacetate. The synthesis of N-phenyl amino pyrimidine derivative 2 was obtained as a result of reaction of aniline with compound 1. Compound 2 underwent ring opening and recyclization upon reaction with HCl or H2O2/ NaOH to afford the acid derivative 3 or oxazine 4, respectively. Thiazine 1 undergoes ring transformation upon the effect of NH2OH.HCl to produce pyrimidine derivative 5. Heterocyclization of compound 1 with thiosemicarbazide followed by oxidation with I2/AcOH afforded triazolopyrimidine 6 and 7, respectively. Alkylation of compound 1 was promoted by reaction of 1 with ethyl iodide to give alkylated thiazine 8 which in turn undergo ring transformation when subjected to reaction with hydrazine hydrate to give pyrazole derivative 9. Refluxing of amino-1,3-thiazine derivative 1 with ethyl bromoacetate in the presence of Et3N produce the alkylated pyrimidine product 10. Hydrazonolysis of 1,3-thiazine 1 with hydrazine or phenyhydrazine gave pyrimidine derivatives 11a,b, respectively. Compound 11b was cyclized with carbon disulfide or formaldehyde to produce triazolopyrimidines 12 and 13, respectively. Some of the new compounds were screened for anticancer activity and significant results were found for some compounds.               KEY WORDS: 1,3-Thiazine, Pyrimidine, Triazole, Pyrazole, Anticancer activity Bull. Chem. Soc. Ethiop. 2018, 32(3), 513-522.DOI: https://dx.doi.org/10.4314/bcse.v32i3.1

Synthesis of Dynamic 2-Ethoxycarbonyl-4H-3, 1-Benzoxazin-4-one and its Behavior Towards Nitrogen Nucleophiles

The behavior of  2-ethoxycarbonyl-4H-3,1-benzoxazin-4-one and its behavior towards nitrogen nucleophiles namely, hydrazine hydrate, formamide, benzylamine, ethylamine, piperidine, ethanol amine, o-phenylenediamine, and glucosamine hydrochloride has been investigated. Also the reaction of 3-[aminoquinazolin-4(3H)-one-2-yl]formic acid hydrazide with aromatic aldehydes and phenylisothiocyanate has been discussed. The structure of the prepared compounds are elucidated using physical and spectral data like, FT-IR, 1HNMR, and mass spectroscopy

Recent Advances in Non-Linear Site Response Analysis

Studies of earthquakes over the last 50 years and the examination of dynamic soil behavior reveal that soil behavior is highly nonlinear and hysteretic even at small strains. Non-linear behavior of soils during a seismic event has a predominant role in current site response analysis. The pioneering work of H. B. Seed and I. M. Idriss during the late 1960’s introduced modern site response analysis techniques. Since then significant efforts have been made to more accurately represent the non-linear behavior of soils during earthquake loading. This paper reviews recent advances in the field of non-linear site response analysis with a focus on 1-D site response analysis commonly used in engineering practice. The paper describes developments of material models for both total and effective stress considerations as well as the challenges of capturing the measured small and large strain damping within these models. Finally, inverse analysis approaches are reviewed in which measurements from vertical arrays are employed to improve material models. This includes parametric and non-parametric system identification approaches as well as the use of Self Learning Simulations to extract the underlying dynamic soil behavior unconstrained by prior assumptions of soil behavior

Networked Geotechnical Near Real-Time Monitoring for Large Urban Excavation Using Multiple Wireless Sensors

A massive urban excavation is required to construct the below-grade rail platforms for the Transbay Transit Center. A performance-based approach was used to design the minimum stiffness of the shoring system to limit excavation-induced ground movements to appropriate magnitudes and minimize impact to adjacent infrastructure. During construction, a fully-automated near real-time digital geotechnical monitoring system that integrates wireless sensor data streams into an integrated database and decision support system called the Global Analyzer is used to track the performance of this excavation. Instrumentation used for monitoring includes inclinometers, deep settlement markers, extensometers, piezometers, and an automated total station network. Some of the advantages of the Global Analyzer system include (a) integration of all project monitoring data and construction history information in a centralized database, (b) the ability to compare measured and estimated or target performance, (c) the use of early indicators to understand problems areas prior to excavation reaching critical stages, (d) the distribution of geotechnical monitoring data to adjacent building owners and other stakeholders through a web-based portal, and (e) the generation of computer generated email alerts when threshold values are exceeded by a given instrument. The Global Analyzer is a key tool in supporting an efficient decision process informed by more complete and timely performance data. It represents a component of the decision support process needed in the observational approach and deformation control. This application is relatively new to such a large scale project in the US and provides an example of a large complex data collection and distribution system. The monitoring process used for this project takes advantage of the latest communications technologies in the monitoring of the construction of the Transbay Transit Center excavation in its complex urban environment