Seismic multiples

As of this writing, it has not been possible to use the seismic data which defines the volume of the reservoir to also determine the joint stmcture. Extended flow testing is the most direct measure of the efficiency and sustainabiUty of energy recovery from the reservoir. The use of chemical tracers in the circulating fluid can also provide valuable supporting data with regard to the multiplicity of flow paths and the transit time of fluid within the reservoir (37). 

This isothermal bulk modulus (Kj) measured by static compression differs slightly from the aforementioned adiabatic bulk modulus (X5) defining seismic velocities in that the former (Kj) describes resistance to compression at constant temperature, such as is the case in a laboratory device in which a sample is slowly compressed in contact with a large thermal reservoir such as the atmosphere. The latter (X5), alternatively describes resistance to compression under adiabatic conditions, such as those pertaining when passage of a seismic wave causes compression (and relaxation) on a time-scale that is short compared to that of thermal conduction. Thus, the adiabatic bulk modulus generally exceeds the isothermal value (usually by a few percent), because it is more difihcult to compress a material whose temperature rises upon compression than one which is allowed to conduct away any such excess heat, as described by a simple multiplicative factor Kg = Kp(l + Tay), where a is the volumetric coefficient of thermal expansion and y is the thermodynamic Griineisen parameter. 

Bina C. R. (2002) Phase transition complexity and multiple seismic reflectors in subduction zones. Eos, Trans., AGU 83(47), Fall Meet. Suppl., Abstract S52C-05. 

As shown in this figure, the structure of the seismic line has a thin volume by 20 x 80 x 400 m, which consists of the sub parallel multiple clusters shown in Figure 7 (a). The cluster found by Phillips (2000) is included in this volume at the depth around 3200 m. 

Heavy vessels (single large vessel or multiple large vessels) The vessel(s) is the principal vibrating element. It requires a combined seismic model, which simulates the mass and stiffness properties of vessel and structure. 

The flg multiplication factor applied to the spectral form is defined as a function of the return period and of the seismicity level S foreseen by the current seismic classification of the national territory. The values to be used are listed in Table 15-4. 

Section 3.3.2.3.5, Accident Selection, identified one beyond DBA as, Multiple simultaneous errors or events that affect multiple SCBs, resulting in release of the contents of multiple targets. Release of the fission products from multiple targets (six) in a single SCB has already been analyzed in two DBAs Spill of Process Materials in an SCB and Fire in a Process SCB. The source term and consequences of the Multiple simultaneous errors or events... beyond DBA are discussed in Section 3.4.3.1 and S.4.3.2 below. Two additional hazards are discussed in Sections 3.4.3.3 and 3.4.3.4 as beyond DBAs to provide a perspective of the residual risk associated with the operation of the facility. These beyond DBAs are 1) seismic events resulting in a release of radiological material and 2) dispersal of radiological material by an explosion in the HCF. 

Seismic action can cause serious accidents to industrial plants as shown in several occasions. The actual worldwide situation of major-hazard plants against earthquakes should be considered as critical. For instance, in Italy about 30% of industrial plants with major-accident hazards are located in areas with a high seismic risk. In addition, in case of a seismic event, the earthquake can induce the simultaneous damage of different apparatus, whose effects can be amplified because of the failure of safety systems or the simultaneous generation of multiple accidental chains. 

P = internal pressure, psi Ch = horizontal seismic factor Cv = vertical seismic factor Cc,Ci. = multiplication factors for and Nx for rectangular attachments... 

One of the methods developed for the seismic risk evaluation of structures is the SAC-FEMA method, which enables probability assessment in closed form (Cornell et al. 2002), and represents a part of a broader PEER probabilistic framework (Deierlein 2004). Within the framework of SAC-FEMA method, the relationship between the seismic intensity measure and the engineering demand parameter is usually determined by Incremental Dynamic Analysis (IDA) developed by Vamvatsikos Cornell (2002). IDA is a powerful tool for estimation of seismic demand and capacity for multiple levels of intensity. However, it requires a large number of inelastic time-history analyses (and corresponding detailed data on ground motion time-histories and hysteretic behavior of structural elements) and is thus very time-consuming. Often it is possible to create summarized IDA curves with less input data, with less effort, but with still acceptable accuracy. One possible approach is to determine seismic demand for multiple levels... 

Wang, J. K, Lin, C. C. (2005). Seismic performance of multiple tuned mass dampers for soil-irregular building interaction systems. Inter-nationalJournal of Solids and Structures, 42(20), 5536-5554. doi 10.1016/j.ijsolstr.2005.02.042... 

It is notable that other factors can be added for assessment ifnecessary, such as lateral seismic input, multiple-point seismic input, shear force at the base of the tower, displacement response at the middle of the deck and displacement response at the top of the tower, etc. 

Chen, G., Wu, J. (2001). Optimal placement of multiple tuned mass dampers for seismic structures. Journal of Structural Engineering, 127(9), 1054-1062. doi 10.1061/(ASCE)0733-9445(2001)127 9(1054)... 

Rama Mohan Rao, A., Sivasubramanian, K. (2008). Optimal placement of actuators for active vibration control of seismic excited tall buildings using a multiple start guided neighbourhood search algorithm. Journal of Sound and Vibration, 377(1-2), 133-159. doi 10.1016/j.jsv.2007.08.031... 

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