Current World Environment

Introduction

Construction is majorly supervised by construction engineering organization in Iran and the organization members, based on issued licenses, can perform their specified tasks. The availability of various tasks and experts in this area has made it possible to minimize the defects of buildings and their linking spaces by creating comprehensive procedures in passive defense. Given that the main factor in raising the construction quality and subsequently the social welfare is enhancing the quality of work and material, this factor is now receiving special attention in different countries. Urban centers and hotspots in developed countries always receive great deal of attention for being reinforced and resistant against military attacks. Shelters in most city centers are often highly apparent (like in Switzerland). It is inevitable to equip open spaces and build a set of linking networks based on availability and flexibility as necessary and useful measures for preserving and sustaining the urban neighborhoods. (Jafari et al.,2013)

Passive Defense Requirements in Urban Construction

Urban constructions can be categorized into three major classes

1. Urban blocks: the smallest set of integrated construction or land segmentation in a way that each segment is restricted by several passages.
2. Segments: a piece of land with specified borders having document of title and approached to at least one passage.
3. Buildings: set of structures built on the land for residential or non-residential purposes (administrative, commercial or cultural, for instance).

The important point to be noted here is that passive defense may primarily be used as a kind policy to reduce the consequences of a human disaster, like war for example, even before its breakout. Secondly, although the use of passive defense is popular in urban and macro levels, this solution can be applied in urban blocks and their features. Also knowing the defense instructions with regard to the size of blocks, segments and buildings, buildings form and density, the location of building and segment and so on, is of great importance.(Moafi et al., 2011)

Principles of Passive Defense

1. Selecting the safe geographic areas of a country
2. Determine the optimal scale of population and space activities
3. Distribution of the functions with threats and geography
4. Small and inexpensive construction and initiative in passive defense
5. Economic feasibility of the project
6. Parallelism associated support systems
7. Retrofitting structures
8. Positioning of operations
9. Crisis defensive management in scenes
10. Camouflage and concealment
11. Destruction of enemy intelligence system
12. Concealment using natural and geomorphologic features
13. Initiativeness and diversity in all actions
14. Protection of critical information systems
15. Production of dual purpose structures.

The Approach of Different Countries Toward Passive Defense

China

The indication of china's passive defense performance is important because of the fact that even a country like China with such military capabilities feels the necessity for passive defense. There have been built various shelters across urban regions of China, particularly in Beijing, which are divided into two types:1. Shelters in large residential complexes,2. Public shelters; most recently built residential or commercial complexes in Beijing have several underground stories currently used as parking lots which are connected to subway network.

USA

passive defense became more important and popular in the US in early 1960's and after the emergence of tension between the two powers of east and west. During the presidency of Carter and Reagan, passive defense became important again with the emphasis on these three reasons: a. passive defense is a significant part of deterrence theory; b. passive defense is an important instrument in crisis management; c. passive defense in the focal point for country's sustain and survival.

North Korea

it has concealed the critical facilities in 80 to 100 meter depth underground tunnels under the volcanic mountains.

Switzerland

passive defense in managed by "the Federal Department of Civil Defense". The objective of passive defense programs in Switzerland is to supply shelter against explosions for each individual of its 6.5 million population with the financial contribution of the owners as 50% of total expenses.

Israel

since its foundation in 1948 it has always been endangered by Arab neighbors particularly across the borders. Thus, passive defense has always been an indispensable part of country's preservation strategy. (Mohammadi et al, 2009).

The following table describes different measures of passive defense adopted by some countries.

Table 1: Passive defense measures in different countries (Yeganegi et al.,2011)

Passive Defense in Iran

the teachings of Islam has prohibited Muslims of any bellicosity, however, it puts more emphasis on defending their lives, property and prestige. After announcing Iran as "the axis of Evil" by the US, the importance of being alert and prepared to defend has duplicated in Iran. (Mohammadi et al, 2009)

In fact, different stages of passive defense plan are prepared and implemented before any invasion and at the peacetime. Given the great time and opportunity available for such plans before any malicious violations, various measures should be considered within the context of planning. Today the basic measures of passive defense like camouflage, concealment and so on do not encompass all aspects of a comprehensive passive defense plan and thus, the Expediency Counsel of IR, has provided new definition for passive defense: "it includes decreasing the vulnerability, raising national endurance, continuing the activities, and facilitating the servicing and crisis management". Raising the national endurance does not necessarily means military preparation, but it also encompasses political, economic, social, and cultural measures. (Kazemian et al., 2012)

Considering the weight of international threats facing the IRI, we are still at the beginning of a long journey in the process of passive defense, and increasing the knowledge level of managers and experts about passive defense can elevate the safety level against any possible foreign threat. As stated by the head of standing committee of Iran passive defense, due to the lack of an identical recognition of threats and kind of uncertainty in this area after the Islamic revolution, a great deal of construction was performed in vulnerable areas and different economic or civil projects were conducted regardless of the aspects of passive defense. With respect to the high level of threats and dangers targeting our national security, independence and sovereignty, the issue of passive defense has received so much attention from military and non-military authorities in recent years. The potentials of subsurface spaces and fundamental principles of passive defense are bound together in such a way that make it necessary to be executed for realization of the developmental needs.( Salek Ahmadi et al., 2011)

Passive Defense in Ancient Iran

During the Median era passive defense was primarily relying on retrofitting the constructions and military castles, while Parthian put more attention on battlements and using different approaches o decelerate the enemy access such as digging ditches as a sort of passive defense solution around the castles. In Sasanian era, in addition to the mentioned measures, more stress was on the construction of long and thick walls like Gorgan wall besides castles. Also, changing the internal systems of castles such as complex underground traffic system can be considered as another feature of passive defense during this historical era. Regarding the excavated features from ancient structures, it can be inferred that the passive defense considerations had kind of incremental trend in each era.

The following table provides a comparison between the passive defense features of three mentioned eras. (Khodaparast et al., 2012)

Table2: The comparison between city-fortress in ancient Iran (Khodaparast et al.,2012)

Studying Sample Population of Construction Engineering Organization Members

With respect to the importance of recognizing the passive defense and its application in national construction, the author has conducted a survey on the level of knowledge about the application of passive defense measures in the industry among the members of Iran Construction Engineering Organization. The results of the survey which is collected from 380 engineers, is illustrated in the following graph.

Figure1: Resposes  Click here to View figure

It can be seen from the graph that there is an emergent need to put more stress on training the engineer community. Considering the working conditions, such trainings can be in the form of Leaflets and Catalogs offered at special meetings, publishing specialized books and magazines in this field, and also refreshment training s and notes via periodic SMSes in a way that can be properly utilized by the experts in construction sector.

Conclusion

As mention in the context, considering various measures of passive defense has always existed from a historical point of view, and different countries including developed and developing ones, are now putting more emphasis on it. Fortunately, in Iran, both prior and after the impose war by Iraq, passive defense has often been considered in buildings and facilities but there is still a long way toward achieving the desirable goal. The necessity of instruction and training for the society is one of the most significant factors and with respect to the critical role of engineers in the construction industry they must pay more attention to learning and observing the regulations in this field. The officials and authorities should also provide the requirements in such a way that necessary information in this regard can be well transferred to the engineer society.

References

1. Jafari, Y. Hesami , A. the evaluation of various structures in urban neighborhoods from passive defense point of view. Iran's geopolitics association congress. Mashad, Iran (2013).
2. Kazemian, M. Hafezian, M. Kazemi Kani, B. Mirmotahari ,s. Rostamian,S. studying the importance of passive defense, global identity paradigm from Islamic point of view. Iran’s geopolitics association congress. Mashad, Iran (2012).
3. Khodaparast,M. Nayebosadrian ,F. passive defense in ancient Iranin Architecture. the national conference on sustainable construction and development. Mashad. Iran (2012).
4. Mafi, A. Davarinejad Moghadam ,M . and Mabhout, M. passive defense requirements in designing urban buildings and blocks. The national conference on sustainable construction and development. Mashad. Iran (2011).
5. Mohammadi, A. Bayati Sedaghat, Z. AghaAliKhani, M. passive defense in different countries( in introduction to passive defense solutions). land preparation. passive defense. remote sensing (2009).
6. Salek Ahmadi, M. providing a multipurpose design pattern for urban subsurface spaces at normal and critical circumstances. college of Urban construction. Iran's University of science and industry (2011).
7. Yeganegi, K. and Bayat, E.Evaluation of urban management with passive defense approach.Third National Conference on Urban Development, Islamic Azad University of Sanandaj. Sanandaj, Iran (2011).