Earthquake Condition: Study of Mirpur and Mohammadpur Area

General

Earthquake occurs because of the movement of the surface of the Earth and various changes in soil layers. Most earthquakes are so faint that they can be detected with only sensitive instruments. When an earthquake of fearful Richter scale occurs, the Earth under our feet trembles, buildings collapse causing deaths and injuries, inducing fires, producing floods from collapsed dams and lands and so on. Specialist scientists usually work on prediction, frequency, planning of land-use, hazardous structure, warning signal, earthquake insurance, and provide safety tips, and advocate research, study of the impact of earthquake. They also prescribe emergency operation and advise legislative procedure, and perspective of quake-facing administration and preparedness planning. Their vulnerability analysis, shelter system, safety of food and medical services for victims are highly respected by public welfare-oriented administration.

Rationale of the study

Unplanned urbanization and lack of rescue preparedness make the city extremely vulnerable to a disaster with colossal loss of lives and property. Earthquake hazard cannot be identified before it put its catastrophic step on the earth. So it is necessary to distinguish the possible approaches to minimize the earthquake damage by earthquake risk analysis and mitigation. The need for placing more emphasis on conceptual design and seismic load bearings involve the structural engineering and constructional perception of the infrastructures.

Objectives of the study

• STUDY 1 : To address and assess the possible impacts of earthquake hazard on critical infrastructure (educational instituitions and health facilities of Mohammadpur and Mirpur area.
• STUDY 2: To compare the impact of Mohammadpur and Mirpur area.
• STUDY3 :   To recommend some proper earthquake preparedness, risk mitigation plan and policies, emergency response and recovery for critical infrastructures.
• STUDY 4 : vulnerability to the place and peapole.
• STUDY 5 : appoarch  to manage earthquake vulnerability of these area.

Source: Banglapedia

Source: DMB

General

 Methodology describes the strategies or the working procedure of the study in a systematic manner to reach the goals and objectives. Methodology is the most important part for any research work as the quality and the expected outcome of research depend on it and a well designed methodology helps the researcher to work smoothly.

Stages

This research comprises four major stages of work. They are:

• Conceptualization.
• Collection of Primary and Secondary Data from different source.
• Analysis of the collected data.
• Recommendation and Conclusion

Conceptual framework development

Every research is generally based on some specific concepts, which direct the approach of the research work. According to this study, the structure of the research work is dependent on the several terms of Earthquake, earthquake mitigation plan, disaster management and strategies. This research is concerned with the post- earthquake impact on the critical infrastructure and lifeline support of particularly Mohammadpur and Mirpur area.

Literature Review:

An extensive and sophisticated survey was carried out to have a basic knowledge about earthquake disaster, critical infrastructure and lifeline of the study area and the probable impact on them after an earthquake. This include several thesis paper, research work, different government study, disaster related books, seminar papers, articles, journals, newspapers and websites.

 Approaches to fulfill the objectives

The several approaches for fulfilling the objectives as mentioned in chapter one are précised below in table.

Table 1: Objectives Matrix

Selection of the study area

Ward no 8:

This ward is located in the western part of Dhaka city. This ward contains the areas of Mirpur named Uttar Bishil area, Shah Ali housing estate area, Shinepukur Housing Estate area, Block –Ka, Block-Kha and Block- A, B, C, D, E, F. The area has several low lands and waterways. The famous National Zoo and Botanical Garden area is included in this area.

Ward no 46:

Ward no 46 is located in the south western part of Dhaka city. This ward contains the areas of Mohammadpur named Bosila, Mohammadi housing, Bashbari, Chan mia housing, Kaderiabad Housing Society, JapanGardenCityetc. This area has also several waterways and important Launch Terminal of BIWTA. This ward is attached with the BurigangaRiver by a side.

The critical infrastructures that are taken into account in this thesis are, Educational Institutions and Healthcare Facilities in Mirpur and Mohammadpur area. The overall descriptions of the areas are given below:

Ward no 8

Source: DCC

Ward no 46

Source: DCC

Collection of information

To investigate the entire circumstances of Earthquake Hazard of Mohammadpur area, Dhaka city, different documents, maps, satellite images, data and information have been collected from different related organizations. To make the data collection process easy, this process have been divided into two categories.

Primary information collection

The existing situation of critical infrastructure and lifeline support has been collected by several sources. The socio-economic condition, awareness and response of the people in respect of disaster are assembled. Information is collected by field survey and other offices. The study also includes opinion of specialists on disaster management and earthquake issue.

Secondary information collection

To investigate the frequency of occurrence, magnitude, intensity and historical background of earthquake, data and information are collected from different related organizations such as, Disaster Management Bureau (DMB), Bangladesh Earthquake Society (BES), Bangladesh University of Engineering and Technology (Buet), Dhaka City Corporation (DCC), Ministry of Food and Disaster Management (MoF&DM) etc. related websites are searched to collect data and information about earthquake and disaster management.

 Data Analysis

The compilation of the information was investigated and then edited, coded and computerized. Analysis is done by MS EXCEL and SPSS software was used to produce the output of earthquake vulnerability assessment.

 Understanding the situation

The information about the earthquake and its possible impact is being analyzed. It represents the current situation of the earthquake management of the particular area as well as Bangladesh. It also discloses the awareness and response about the mitigation plan of earthquake among the general people which tends to comprehend the perspective of disaster management of our country.

 Evaluation of the present situation

The existing situation of the disaster management has been assessed through the light upon the study area. It helps to describe the preparedness program, response, recovery process etc.

Investigation of the problem

On the basis of collected data and information the problem of earthquake in Mohammadpur area is investigated and determined.

Formulation of guideline to improve the condition in the future

The guidelines are formulated with regard to the problem assessed by the vulnerability assess ment model of the study area. Future guidelines are suggested for the mitigation plan considering the priority issues.

Report Writing: currently finalizing of all required maps, tables and charts are done. The thesis’ is organized into different chapters in a consistent way. Initially a draft of the dissertation was presented and finally the final dissertation is submitted for examination.

Report writing

At the same time as, finalizing of all required maps, tables and charts are done. The thesis is arranged in different chapters in a coherent way. Initially the draft of the dissertation was presented and finally the final dissertation is submitted for examination.

Overall Analytical Description of the Study Area

The analytical examination was done by the SPSS 12.0 Software of the existing two areas. The analytical study has been showed over here by comparing the two areas of Mirpur and Mohammadpur. The overall critical investigation has done into two portions.

• Charts &
• Tables

Types of buildings in Mohammadpur and Mirpur area

Here we can see the Types of the Buildings of Mohammadpur and Mirpur are different in nature. Both of them contain three types of building like RCC, Masonry and Semi pacca building but they are different in amount.

• Year of construction

Year of construction are different in nature. It is observed that both areas have less old buildings of around eighty years old. Mohammadpur has a large amount of buildings that are built within last twenty years. And Mirpur has highest amount of buildings constructed around last forty years. Both has almost same amount of buildings that are constructed within last fifty years.

• Symmetric characteristics of buildings

According to this survey and the pie charts below, it is obvious that most of the buildings of Mohammadpur are not symmetric. In Mirpur area, comparing to Mohammadpur, the buildings are more symmetric. The difference can be better showed off in the tables later.

Table 2: Symmetric buildings of Mohammadpur and Mirpur

 Presence of shear wall at the middle

Shear wall is an important feature for any building to resist the building from earthquake hazard. Shear wall should be provided at the middle. According to the survey, in Mohammadpur, almost all building was constructed without any shear wall. Those which have shear wall are not put into the middle which is harmful. In Mirpur, there was no existing building of survey criteria’s which have shear wall. 100% buildings that are surveyed in Mirpur were built without any shear wall.

Table 3: Mohammadpur and Mirpur(shear wall)

• Presence of cantilever beam

The presence of Cantilever Beam is might be harmful or not. But they should be properly planned and endowed with proper structural load bearing capacity so that they won’t harm the building while Earthquake.  According to our survey areas, in Mohammadpur, it’s obvious that almost half of the buildings are without cantilever beam, the rest are present but not so harmful and a few buildings have harmful cantilever beam. In Mirpur area the greater part has no cantilever beam and the rest of the part is divided into half in which one part is harmful and the rest of the half is not so harmful.

Table 4: Mohammadpur

Table 5: Mirpur

• Apparent quality of the buildings

The apparent quality of the buildings of Mohammadpur and Mirpur, are surveyed and showed below. According to this survey, in Mohammadpur greater numbers of buildings are medium, half of the rest are bad and worst and some are good in condition. In Mirpur, almost half of the buildings are good in apparent quality, half of the rest are worst and a few buildings are bad in quality.

Table 6: Apparent quality of Mohammadpur

 Table 7: Apparent quality of Mirpur

 Use of buildings

According to the survey and the pie chart below, it is showed that the use of the buildings of Mohammadpur and Mirpur area, are divided into primary school, secondary school, college, other educational instituitions and health care centres.

• Floating columns

Floating columns might be very harmful for the Earthquake Hazard.

• Presence of flat plate

Flat Plate is a flat, reinforced-concrete structural member, relatively sizable in length and width, but shallow in depth; used for floors, roofs, and bridge decks. Flat plate means generally, a concrete slab which is provided instead of heavy beams. Sometimes for viewers choice, instead of beam, Flat plate is given as priority. In Mohammadpur and Mirpur area, the usage of Flat Plate is not so high but its alarming that this number buildings are increasing.

• Large openings

Large openings are harmful for buildings during earthquake. According to the survey, in Mohammadpur area large openings are comparatively less than Mirpur area.

• Irregular openings

Irregular openings are also harmful for buildings. According to the survey, Mohammadpur area contains more irregular openings in buildings than Mirpur area.

• Corner openings

An opening at corners of a building is harmful during earthquake. In Mohammadpur area, the openings at corners of buildings are greater than Mirpur area’s buildings.

Table 8: Mohammadpur

 Table 9: Mirpur

      Existence of long walls

Existences of Long walls in buildings are harmful also. According to the study, Mohammadpur area consists of greater number of buildings that have Long walls which are harmful, than Mirpur area.

• Dissimilar buildings

Dissimilar buildings of Mohammadpur and Mirpur areas are compared below and the result shows that Mohammadpur area included greater part of dissimilar buildings.

Table 10: Mohammadpur and Mirpur

 Roof condition

Roof condition of Mohammadpur area are almost medium, the rest of the pie chart is good, worst and tinshade. In Mirpur area, most of the building’s roof conditions are good, rest of the chart is medium and worst and a few buildings are tinshade.

Earthquake band

According to the survey, the buildings of Mohammadpur comparatively contain more earthquake band in foundation level and three levels of foundation, plinth and lintel. The buildings of Mirpur contains earthquake band in a smaller level.

Table 11: Mohammadpur

 Table 12: Mirpur

 Accessibility of buildings

Accessibility of a building means the entry and exit of any building. In this study, it was prior that, in Mohammadpur almost all buildings have partial access whereas in Mirpur, most of them have full access. But in Mirpur, some of the buildings have no access and they are declared as abandoned.

 Seismic Vulnerability Analysis

General

According to the RVS method, the Vulnerability class is identified by the pie charts and tables below of Mirpur and Mohammadpur areas.

• Vulnerability Class of Mohammadpur area

Table 13: Vulnerability Class of Mohammadpur (table)

• Vulnerability Class of Mirpur area

Table 14: Vulnerability class of Mirpur area (table)

   Stady: Vulnerability to structure

According to the survey, it was apparent that the vulnerability of the structures is more or less related to their construction materials, soil and land use, building maintenance, proper and planned way of construction etc. Mirpur and Mohammadpur, these two areas are different in their nature of growth. Because, Mirpur, ward no-8, is a planned area and Mohammadpur, ward no-46 is developing nowadays.  So they are quite different in their building patterns and qualities. From the survey, its noticeable that highest vulnerable structures in Mohammadpur and Mirpur  are five and lowest vulnerable structures in Mohammadpur are only two whereas Mirpur  has six structures within the surveyed buildings.

 Vulnerability to Place and People

Some 1, 30,000 people could be killed right away if an earthquake of 7.5 magnitude, originating from the Madhupur blind fault, strikes capital Dhaka in the daytime, a survey says.
The number of deaths will be a touch less, around 1, 22,000, if the tremor takes place at 2am. In this study, it has been observed that Mirpur and Mohammadpur, both are residential area almost. So the structural deficiencies of the buildings of these two areas might become very much harmful and terrific if any strong Earthquake occurs. The people of these areas will be in danger if the vulnerable buildings are not retrofitted or alternated by other buildings.

When an Earthquake will occur, both Mirpur and Mohammadpur areas will be in great chaos because both of them are major part of economical, social and cultural activities.

In Mohammadpur

a)      Mohammadpur area consists of multi-storied buildings of JapanGarden city which is very much dissimilar according to its height and the adjacent other buildings.

b)      Besides this, the primary schools are very much vulnerable and harmful. Already there are lots of cracks and the glasses of the windows are already broken by some minor earthquake.

c)      The secondary schools are almost good but other educational institutions are mixed in nature. Some of them are vulnerable.

d)     Some roads are very congested which might become problematic for reaching the rescue team while earthquake hazard. Hence, fire hazard may occur from the lifeline and utility services during earthquake. This fire hazard will be also harmful for the people and the place as fire brigade may not reach there at time.

e)      Beside this, the healthcare centers are not in a good condition which may lead the patients to death or injury when an earthquake occurs.

In Mirpur

a)      The primary schools of Mirpur are in vulnerable position. Already the buildings are being repaired by the authority but still they are not so satisfactory.

b)      The secondary schools and colleges are almost good in condition as they are recently built. Hence, the road conditions are not so pleasing for the earthquake rescue team to move during a major earthquake happens.

c)      The buildings are dissimilar in nature according to their adjacent buildings and the locality.

d)     The Government Shelter Centre at Mirpur-1 is a building of 100 years ago which was a mosque for the Sunni Muslims. Later on this is now used as the shelter centre which is vulnerable for lots of girls who are dwelling over here.

e)      The shopping complexes are also at risk for other critical infrastructures and roads also, for earthquake hazard.

  Study : Earthquake preparedness and emergency facilities

Around 250,000 buildings in the three major cities of Bangladesh—Dhaka, Chittagong and Sylhet—are extremely vulnerable to earthquakes, according to a recent survey which was the results of the survey, carried out under Phase-1 of the CDMP. Around 78,000 out of 326,000 buildings in Dhaka were detected as risky as the purpose of the recent study was to detect vulnerable buildings. From another source, around 7 to 7.5 on the Richter scale will devastate about 72,000 buildings in the capital. (bdnew24.com, 28 august,2009,viewed on 15January,2010)

According to the study, if,

*6-magnitude earthquake shakes Dhaka originating from it’s beneath, causing havoc throughout the densely populated capital city, some 78,323 buildings will be destroyed completely.

* 7.5-magnitude earthquake originate from Madhupur Fault, will kill some 131,029 people instantly and injure 32,948 others. Some 72,316 buildings in the city will be damaged totally while 53,166 partially.

* 8.5-magnitude of tremor from the plate boundary of Fault-2 hits the region, some 238,164 buildings will be destroyed completely across the country.

*According to the study, at least 10 major hospitals, 90 schools in the capital will be destroyed completely and another 241 hospitals and clinics, 30 police stations and four fire stations partially in case of a 7.5 magnitude quake.

The economic loss will be about US $ 1,112 million for only structural damage in case of a 7.5-magnitude earthquake from the Madhupur Fault, it estimates. “Economic loss due to damage of structures will be US $ 650 million and US $ 1,075 million respectively in case of an 8-magnitude earthquake from the plate boundary-2 and in case of a 6-magnitude earthquake from under Dhaka city,” the study says. A strong earthquake of 8.6-magnitude occurred in Assam on August 15 in 1950, killing 1,526 people. Another 8.1-magnitude quake hit Assam on June 12 in1897, killing 1,500 people. The casualties were less because of low density of population and fewer numbers of concrete structures at that time.

Referring to three major earthquakes of the region, a powerful earthquake needs at least 100-150 years to be originated for a particular region and in that sense it is overdue for Bangladesh and parts of Assam, as 112 years have passed by since a heavy tremor from Dawki Fault hit the region. The need for demolishing old and risky buildings of the city and to build the structures according to the BNBC rules is prior nowadays.

Experts observed that though disaster assessment has moved ahead with the survey, there have been hardly any tangible measures taken by way of disaster preparedness.

On its part, the housing and public works ministry has initiated programmes to reactivate the building code, which was formulated 16 years back. A work order has been circulated and an advisory body formed to revise and update the existing code. Officials said the process will end sometime next year.

RAJUK, the city corporations and other concerned government agencies have to come forward in a coordinated move to ensure strict compliance with the building code.

Volunteers should be trained and equipment should be collected and distributed under the CDMP, as volunteers are the foundation to fight a “sudden” disaster like earthquake.

Directions on how hospitals, fire service and rescuers, including the armed forces, will respond to an eventual disaster will have to prepared.

It’s been a matter of pleasure that the government has already started to build a 62,000-strong volunteer corps within the next few years while the fire service and civil defense department are being equipped with search and rescue tools under the CDMP.

The government has recently approved an additional Tk 70 crore to procure more sophisticated rescue equipment for the defense forces to handle any major earthquake disaster.

Rescue training activities and advocacy campaigns among the decision makers, planners, teachers and school children are being conducted in the risky zones of Bangladesh—Dhaka, Chittagong and Sylhet—to reduce urban risks in the event of any major earthquake.

An Earthquake Contingency Plan has been developed through training programmes and exercises are being conducted to implement the plan effectively. The draft National Plan for Disaster Management 2008-2015 is underway, which will be finally approved by the government, containing an earthquake management plan.

Buildings that are vulnerable should be retrofitted to avoid possible damages from Earthquake. Retrofitting refers to the idea of addition of new technologies and features to old system. According to structural engineering, Retrofitting means the reinforcement of structures to become more resistant and resilient to the forces of natural hazards.

Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged.

Gas leakage management, power supply control, firefighting, alternative power generation, and wireless communication system, heavy equipments for removing debris and emergency clinical facilities are the top priority areas for attention.

Study:  Approaches to manage Earthquake Vulnerability

Step 1: Securing Now

Reducing and/or eliminating hazards throughout home, neighborhood, workplace and school can greatly reduce risk of injury or death following the next earthquake or other disaster. Conducting a “hazard hunt” might be helpful to identify and fix things such as unsecured televisions, computers, bookcases, furniture, unstrapped water heaters, etc. Securing these items now will help to protect from any hazard.

Step 2: Making a plan

Planning for an earthquake, terrorist attack, or other emergency is necessary for any family. The emergency plan should include evacuation and reunion plans, the location of emergency supplies and other pertinent information.

Step 3: Making of disaster kits

Everyone should have disaster supplies kits stored in accessible locations at home, at work and in their own vehicle. Having emergency supplies readily available can reduce the impact of an earthquake, a terrorist incident or other emergency on a person. The disaster supplies kits should include food, water, flashlights, portable radios, batteries, a first aid kit, cash, extra medications, a whistle, fire extinguisher, etc.

Step 4: Ensuring the safety of living place

Most houses are not as safe as they could be. Whether homeowner or a renter,t he important things that can be improved to maintain the structural integrity of home, should be prior.. Some of the things that might be important to consider are, checking include inadequate foundations, unbraced cripple walls, soft first stories, unreinforced masonry and vulnerable pipes. Consulting a contractor or engineer might be helpful to you identify building’s weaknesses and deficiencies.

Step 5: DROP, COVER, and HOLDON idea

Learning of the steps to do during an earthquake, at home, at work, at school or just out and about, taking the proper actions, such as “Drop, Cover, and Hold On”, can save lives and reduce the risk of death or injury. That means, during earthquakes, dropping to the floor; taking cover under a sturdy desk or table, and holding on to it firmly, might reduce the risk.

Step 6: Checking it out

One of the first things that should be done following a major disaster is to check for injuries and damages that need immediate attention. Training in first aid and in damage assessment techniques will be helpful in this aspect. To administer first aid and to identify hazards such as damaged gas, water, sewage and electrical lines are also important.

Step 7: Communicate and recover

Following a major disaster, communication will be an important step in recovery efforts. For most presidentially declared disasters, resources will also be available from federal, state, and local government agencies.

Case study-1

Mr. Roni Alam, 40 years old. Though he looks younger than his age. He lives in Mirpur area. With his family members. He is owner of his 10 storied building. When I ask some question related to the earthquake. I can realize that Mr. Roni Alam is not concerned about earthquake and the affect of the earthquake.

Case study-2

Mr. Abdul Kheleque, 52 years old. Home owner of the building live in the 3^rd floor. When I ask some question about earthquake he accepts it very easily and ensures some good answer about it. He is concerned about earthquake. He gave me some advice what government should take for the betterment.

Case study-3

Mr. Sohel Alam, age 30 years old, live in Mohammadpur. he stay is 12^th floor with his friends. When I ask different relevant question. He was very interested to cover the goal answer. He know well about the hazard on affect or vulnerable condition of the area where he live but he directly said that, this is not depend only his concern this should be the government concern.

Case study – 4

Mr. Sagar Ahmed, aged 28, live in Mirpur-2. He is an engineer. He knows about the rules. How a govt. should gave the permit of the high rise building. Why building code should be maintain. What is the preparedness of the earthquake. He gives a correct answer that now it’s not possible to maintain the building code number because of different corruption the govt. official activities.

 Case study-5

Mrs. Sahjida Khatun, aged 45, live in Mirpur-1. Stay in a 1^st floor of the building. She is Assistant Director of the B.O.U. She know about the earthquake and the relevant subject matter. She know that Dhaka city is being in the present days. She is concern about the affect of the earthquake. She was very busy thats why she gave me only 10 min to the description. After that I can realize that may be people know this is the burring matter how a days but they are not willing to do any thing by their own they all are depend on the government steps what they take or not.

 Case study – 6

Mr. Abdul Ali, age 20 years, lived in Mohammadpur area. Study in the DhakaUniversity in English. When I asked him about the condition of the educational area or campus about the matter of earthquake they told, students or teachers are normally aware about this matter. Sometime they do not different seminar about the affect, Preparedness building condition of Dhaka city and some measure of earthquake. But he add that the govt. should be more aware about this topic and the high rise building should be permitted and building code should be maintained properly.

Conclusion

The above study will be helpful, to emphasize the need of identifying the responsibility that the engineers and planners have to play regarding mitigating efforts of Earthquake. It is not only the basic understanding of the phenomenon of earthquake, its resistance offered by the designed structure, but the understanding of the socio-economic factors, engineering properties of the indigenous materials, local skill and technology transfer models are also of vital importance. In conclusion, therefore, it is vital that the engineering aspects of mitigation should be made a part of public policy documents. Besides this, public awareness and community participation should be built up to improve the condition and the perspective of present Earthquake phenomenon.