رهيافت‌هاي معماري سنتي تبريز براي ساخت و ساز ايمن پس از زلزله؛ مطالعه موردي: كاربست كلاف‌هاي چوبي در معماري خانه‌هاي قاجاري

Traditional Principles of Safe Construction after Earthquake in Old Tabriz; Wooden Coil Technique in Residential Architecture of Qajar Era

هدف نوشتار حاضر تبيين اصول مهندسي زلزله در معماري سنتي تبريز و به‌خصوص مرحله تاريخي بازسازي‌هاي پس از زمين‌لرزه ويرانگر سال 1193 هجري ‌قمري است. اهميت موضوع بحث در اين است كه پس از زمين‌لرزه مذكور، ارتقاي پايداري فيزيكي ساختمان‌ها از طريق بهبود سيستم‌هاي ساخت، به بخشي از فرهنگ معماري شهر تبديل شده و يكي از فنوني كه در اين راستا به‌عنوان راهكار جدي مورد توجه قرار گرفت و پيشرفت داده شد، فن تسليح ساختمان‌ها به شبكه مهندسي شده چوبي (كلاف‌هاي چوبي) بود. در مقاله حاضر مشخص مي‌شود كه اين رويكرد فني، حاصل تفكر خلاق معماران بومي براي پيش‌نهادن راه حلي براي برطرف نمودن بخشي از ضعف‌هاي ساختمان‌سازي رايج در آن زمان بود. تكنيك مورد بحث در ظرف زماني خود، نشان از تدبير و هوشمندي معماراني داشت كه از زلزله درس آموخته و براي مقابله با آن راهكار انديشيده بودند؛ راهكارهايي كه مباني‌شان امروزه نيز با دستاوردهاي نوين مهندسي زلزله تطابق دارد. اما مسيله اصلي مقاله پاسخ به دو سوال است: (الف) سانحه زلزله چگونه و به چه ميزان در بهبود تصميمات سازه‌اي معماران سنتي شهر موثر بود؟ (ب) كلاف‌بندي چوبي به‌عنوان رهيافتي اجرايي در تحقق ساخت و ساز ايمن، مبتني بر چه اصولي بود؟ كار حاضر يك تحقيق كيفي است كه به اقتضاي سرشت موضوع، با روش تحقيق تفسيري-تاريخي به انجام رسيده است.

This paper is aimed at explaining the principles of earthquake engineering in Tabrizʹs traditional architecture, especially in the rebuilding era after the devastating earthquake that happened in year 1779 A.D./1193 A.H. The importance of the point is that after the earthquake, the improvement of the buildingsʹ physical resistance through improved building systems became as a part of the cityʹs architectural culture. One of the techniques in this regard, considered as a serious alternative and progress, was wooden coil technique. This element was designed like an engineering network that organized the part of building’s structural system. This paper describes this technical approach as an indigenous solution to the structural problems, to overcome some of the weaknesses of buildings at that time. The techniques used in those times indicated the logic and intelligence of the architects who had learned from the earthquake and had devised some strategies to deal with it. Their innovation was a great achievement in that time and conforms to modern science of earthquake engineering today. Nevertheless, the main problem of this paper is to answer the following two questions: (1) how and to what degree the occurrence of earthquake was influential in improving of traditional architectsʹ structural decisions. (2) Wooden coil technique as a practical approach in realizing safe construction, was based on what principles? Three principles have been discussed in this paper: (1) creating interdisciplinary discourse between structural engineering and humanities, especially history, can establish new and unknown knowledge path. For example, reviewing and reflecting the historical literature and documents is productive in clarification of some unknown issues in earthquake engineering field. (2) Studying the damaged buildings due to earthquake is of importance for evaluation of technical weaknesses. In fact, this is an opportunity to learn and experience. (3) Structural elements with tensile stress tolerance such as wood, if used in a logical manner (as the wooden coils or frames described in this paper) in construction of masonry buildings, can increase their resistance against earthquake. This paper is a qualitative research that was conducted using interpretive– historical research strategy.