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  • Undergraduate Poster Abstracts
  • Civil Engineering

    FRI-723 UV-BASED TREATMENT FOR EMERGING CONTAMINANTS IN OIL- AND GAS-PRODUCED HYDRAULIC WASTEWATER

    • Adrian Saenz ;
    • Karl Linden ;
    • Sydney Ulliman ;

    FRI-723

    UV-BASED TREATMENT FOR EMERGING CONTAMINANTS IN OIL- AND GAS-PRODUCED HYDRAULIC WASTEWATER

    Adrian Saenz1, Karl Linden2, Sydney Ulliman2.

    1Oklahoma State University, Stillwater, Stillwater, OK, 2University of Colorado Boulder, Boulder, CO.

    In U.S. culture today, it is apparent that society is dependent on petroleum-based products. From fuel to cosmetics, oil is an influential and costly part of U.S. civilization. This has necessitated the development of several modern drilling technologies and, subsequently, the production of hydraulic fracturing flowback fluid (HFFF). HFFF is the result of hydraulic fracturing fluid after its intended use and, due to its large water composition, HFFF has potential for beneficial reuse applications and indirect water conservation. The objective of this research was to evaluate the hydroxyl radical (-OH) scavenging potential of HFFF at strategic points in a treatment sequence to determine if ultraviolet (UV) and UV with advanced oxidation processes (UV/AOP) are viable and economically feasible treatment options for degrading organic contaminates within HFFF. In this experiment, raw HFFF and 3 physically coagulated samples were analyzed to quantify several water quality parameters and known concentrations of -OH scavengers before and after UV and UV/AOP exposure. Additionally, para-chlorobenzoic acid (pCBA) was used as a -OH probe to determine the -OH steady state concentrations for all UV and UV/AOP exposed samples. The 3 physical coagulants studied were 45 mg/L of ferric chloride (FeCl3), 45 mg/L of aluminum chloride (AlCl3), and 45 mg/L of FeCl3 coupled with 1 g/L of powder-activated carbon (PAC). Results showed that FeCl3 coupled with PAC was most effective at reducing turbidity, total iron, and transmittance. However, raw HFFF achieved the highest -OH steady state concentration, despite it having the worst water quality and scavenging potential.

    THU-722 THE EFFECTS OF IRREGULAR PRE-LIQUEFACTION LOADING AND PARTICLE ANGULARITY ON POST-LIQUEFACTION RESPONSE

    • Aqshems Meten Nichols ;
    • Wing Shun Kwan ;
    • Chadi El Mohtar ;

    THU-722

    THE EFFECTS OF IRREGULAR PRE-LIQUEFACTION LOADING AND PARTICLE ANGULARITY ON POST-LIQUEFACTION RESPONSE

    Aqshems Meten Nichols, Wing Shun Kwan, Chadi El Mohtar.

    The University of Texas at Austin, Austin, TX.

    Liquefaction of saturated sand is recognized as a devastating hazard. It is important to assess the characteristics of liquefied soil, which is a topic that hasn’t been comprehensively explored. In current practice, the shear strength of liquefied soil is usually crudely correlated with SPT or CPT indices, for which conservatism is often incorporated. In this study, the investigation of liquefied soil is conducted by monotonic loading following cyclic loading in a triaxial testing setup. The results show that the stress-strain curve has a low stiffness region preceding the dilative response region, which concurs with the existing literature. The testing program encompasses 2 factors that affect the post-liquefaction soil response: 1) preliquefaction loading history, and 2) the sand particle roundness. Three types of loading motion (uniform, taper up, and taper down) were applied to reconstituted loose sand specimens to initiate liquefaction, and monotonic loading was applied thereafter. Two types of sand were used, one with well-rounded particles and one with angular particles. Recent studies in this topic are limited to harmonic motion only. The taper motions are more representative of actual transient ground motions in which the dominant pulses occur during the early or later loading phases. The testing results exhibit that the transition of low stiffness to a dilative response is correlated with the history of pre-liquefaction loading and sand particle roundness. A better knowledge of the stress-strain behaviors in liquefied soil can improve the engineering assessment of geohazards, such as the induced displacement of soil particles during an earthquake.

    FRI-722 FLUID DAMPING SYSTEMS AS ENERGY DISSIPATION MECHANISMS

    • Elizabeth Rodriguez ;
    • Arrik Montijo ;
    • Gilberto Mosqueda ;

    FRI-722

    FLUID DAMPING SYSTEMS AS ENERGY DISSIPATION MECHANISMS

    Elizabeth Rodriguez1, Arrik Montijo2, Gilberto Mosqueda.

    1University of California, Berkeley, Berkeley, CA, 2University of California, San Diego, La Jolla, CA.

    During the last few decades, fluid damping systems have been used as energy dissipation mechanisms. In 1991, these damping devices were implemented into buildings and bridges for hazard mitigation applications. This research provides an analysis of the amplification factor of damper displacement in 2 novel frame configurations. In addition, a comparative study is performed between the novel and classic configurations: diagonal and chevron brace configuration. Key parameters to monitor during experimental testing are frame interstory drift, interstory shear, damper displacement, and damper force. For practical applications, the classic amplification factor values of the diagonal and chevron configurations were 0.799 and 1.000, respectively. The value of the amplification factor of the 2 new structures ranges from 1.2 to 2.6 for each structural configuration. This value is due to the geometry of the frames which affects the efficiency of the systems by amplifying the damper displacement. Amplifying the damper displacement will increase the velocity of the damper, dissipate seismic energy, and decrease the damage into the structure such as light-framed wood structures and multi-storied buildings. Finally, this research also provides an analysis of the efficiency of the system in terms of its linearity and non-linearity for amplification factor.