EARLY OBSERVATION OF EEARTHQUAKE AND PROCESS AUTOMATION

Customer : This project was decided to be developed while we are rescueing people from the below of subsidences. This project is a complicated R&D experiment and its first studies was made in the earthquake region. Our project which had successfull field and laboratory tests was delayed because of the speculative expectations and the lack of confidence to the Turkish engineers.

Goal : The goal in this project is to analyse the data acquired during with a security level of 100 percent and take the precautions with the greatest speed and decrease the number of casualities and damage to the minimum.

Design And Technology : After 17th of august earthquake, our R&D engineers made technological studies about sysmic vibration analysis and tried to find an answer to the question of " Can there be early observation of the earthquake ? " and they reached to serious and applicable results. These can be summarised as " Analyses of the datas ,acquired with the existing high technogies, by specialists and the chain of operations based on the application of a squence of different processes appropriate to the organisation and the individuals.

Since the near history these type of technologies were not being used widely because of their lack of speed and their high prizes. The techolonogies became applicable with the rapid development it the field of microelectronics and computer technologies. This project was developed by our project engineers in the result of careful and long methodical researches based on the scientific data. And all probabilities was analised.

How the system work? : In our system the ground movements is determined by three axial sensors. More than one sensor system were used to distinguish the ground movements from the human origined or other nature origined vibrations like ( thunders, lightning, flash, heavy vehicle noise, a crash in near region and fall of an object nearby ). The datas acquired from the sensors are being sent to the data acquisition module in server computer at the observation center fo sampling. The datas are sent by special cables and Spread Spectrum Frequance Hopping Radio Modems.

This acquired data is being analysed by earthquake early observation and evaluation software developed by E3TAM engineers.

When the primer waves with little and similar amplitudes reached to the system from different points and at the same time, the software assumes that an earthquake will happen and passes to the alarm condition and starts to observe the datas. The acquisition time of these primer waves changes according the deepness of the earthquake from the ground , distance of the cracks projection , the jeological properties of the ground and the intensity of the cracks in Richter scale. It is known that the spreading speed of the earthquake wave is between 1.5 km/sec and 8 m/sec according to the ground type. In this project the spreading speed is assumed as 7km/sec. In our system, sensing of the P wave and starting the necessary controls can be made according to the scenario given by the user. The controls after sensing the P waves is dependent on the requests. Because the Dumy Shut-Down condition and unnecessary panic are significant parameter which must be considered. According to the scientific statistics the greatest destructive S waves arises in average of 3-12 seconds after the P waves. This period changes according the deepness of the earthquake from the ground, distance of the cracks projection, the jeological properties of the ground and the intensity of the cracks in Richter scale.

The main structure of the developed project has many big features from this point. Because it must be known that even you acquire the P wave you can not determine the greatness of the destructivity and the periods of the destructive S waves of an earthquake.

From this reason system analyses the earthquake for 2 seconds after sensing the S waves. During this analyses acquires nearly 600 data sample per second from at least two 3-axial sysmic sensor and the analyses the value of the vibration with the mathematical methods in a detirmined way ( sysmic waves can disappear, even stop and can start again. For example: 17th August earthquake is in this type. The S wave started slowly and increased its intensity and stoped for 5 seconds and started again. The total period was 45 sec including this period )

From this reason this two seconds (which is a boundary and critical time period ) is needed to make the most accurate decision. And it is known that whatever the crack intensity is, the destructive impact is dependent on many factors and mostly on the period of the sysmic waves. ( The other factors can be said as ; quality of the ground, condition of the building, materilization level of the legal obligations, construction quality and the position of the nearby buildings. )

Briefly, the intensity of the earthquake is analysed after the start of the S wave. ( According to the literature unless it is located in the center of the crack with a intensity above the medium, no building is being demolished in two seconds. This spesification is assumed to be the basic criteria in determining the structure of the project. The earthquake intensity can be guessed but for today it is not possible to determine the period of vibration. In this point our project takes on risk according to the scenario. After two seconds, the designed system activates all the controls according to the scenario and observes the sysmic waves instantaneously. If the amplitude increases, upper level of control is activated according to the scenario. ( control levels and control numbers are flexible and can be reset )

The observation continue for 5 seconds after all the waves disappeared. This waiting time can be set. Finally our system decides that the earthquake is over, starts to do many functions as important as the control algorith during the S wave period.

System can make data record for the following scientific research, in S and P wave periods while also making the controls.

To make it possible to minimize the unnatural disasters after the earthquake ( flood, fire, gas leak, massive damage to the building causing later demolition ) information acquired in a period smaller than a small friction of the second are analysed immediately and additional controls are activated according to the scenario and sends the information about the last condition of the data and additional controls to the relevant units ( fire department, find and rescue units, crisis headquarters etc. ) in an appropriate format.

Also in this point the visual control of the building is possible. These information is important for the transportation of the relevant action team to the rigt place at the right time. So the chaos condition after disaster which was experienced many times, will be reduced to the least.

System will carries out all this functions at PC Platform. Systems is protected by many security systems for its operation before, during and after the earthquake. ( like electricity cut, wrong signal detection filter, password, autocontrol features ). The designed project is flexible in the terms of its structure. Even after the installation of the project is finished the new features and functions can be added to the system. The products used in the system was s from the existing systems in the wold and the best quality products were selected. The software is the standart software package for the best R&D organisations and it was selected the " Best test product of the year " by NASA a few years ago. It is a programming language known as LabVIEW. The PC used, is industrial type and designed to work at all field and whether conditionsi, safely and free of any problem. The sensors are the sensors of the best firms in this field on the world.

System's General Spesifications :

" The developed system has the ability to be programmed to different setting values according to P and S wave datas and to make decisions continiously and to make accurate decisions.
" The units used in the system are in the universal standarts and formed of the products with the calibration spesifications guaranteed by the certificates of the producer firms. And they have 100 percent security level.
" The system is expandable, convertable, flexiable and has the ability to answer spesific requests. Special additions can be designed for every organisation, for different goals and scenarios. System has 5 alarm level and 3 relay output for every level as standart. There is password security in the system.
" The acquired information can be analysed from high level, can be controlled, can be updated and interpereted.
" System has the feature of validation.
" The system ,which is going to be installed, can be calibrated for a georaphical area.

What are P and S Waves ?

P wave : The first earthquake wave to reach the recording equipment. Its speed varies from 1.5 km/sec to 8 km/sec. Its granule movements is on the spreading direction. Its destructive impact is very low.

S wave : The second wave to reach the recording equipments. Its speed varies between 60 or 70 percent of the P wave. Its granule movements can be perpendecular, crosswise to the spreading direction. Its destructive impact is high.