Pathology is a crucial basis in the process of restoration of historical monuments. So as just by an accurate pathology, a correct and effective restoration plan will be achieved. Amongst the various and different types of damages occurring in the historic monuments, Structural cracks in the walls are very important and considered as special issues that can endanger the stability and structural balance and speed up the process of destruction. These cracks are caused by disruptions in the stability and balance of walls and each disruptive factor usually leads to one crack. However, in some cases, after occurring instability and cracks in a wall by a disruptive factor, it can be seen that with the growth of cracks, secondary and new cracks have been formed. Therefore it is always the question that what kinds of changes in the static equilibrium of the wall and secondary cracks are due to the formation of the first cracks. Therefore in answer to this question, the study aimed to analyze the formation of secondary cracks in the walls without openings. The method is theoretical and static analysis and it is tried to provide examples through a field study to verify the results. According to the studies, secondary cracks do not occur when ordinary settlement in each of the two ends of a wall or almost the entire length of a wall occurs. Rather we see secondary cracks when the settlement has occurred in the middle of the wall or a long settlement has occurred at the beginning or end of the wall. And also the form of secondary cracks depends on the length of the settlement area in a wall and the form of the first cracks

Development of static analysis and relations between the cracks caused by subsidence in the walls without opening is necessary and unavoidable in the process of restoration of historical monuments, before preparing restoration plan and pathology. In other words, accurate and correct pathology, will determine the success of the restoration plan. Pathology process is an analytical issue which should be based on strong and correct arguments in order to achieve the desired result. the damages that requires reasoning and analytical studies include the cracks which were caused due to subsidence in the walls. Balance of forces of the building is disturbed by subsidence and subsequently, cracks are created. On the other hand, wall cracks can also endanger the stability and balance of the building structure in addition to cause instability by the subsidence, and accelerate the process of destruction by reducing the resistant cross-section of the wall. Therefore, analytical and static study of cracks caused by subsidence in the walls has a special and important place. For this reason, several researchers set to study and static analysis of cracks caused by the subsidence. They have obtained ratios and computations based on the length of the subsidence and height of the wall without opening for their detection and analysis. But the question always is whether obtained equations will suffice to analyze the cracks caused by subsidence in the walls without opening? In other words, is there any other types of subsidence and equations that has not been studied so far? So in answer to the question above, this study aimed to find new equations to expand and complement the existing computations in the cracks caused by subsidence in the walls without opening. The research method in this study is theoretical and static analysis and it is tried to be in connection with the studies of other researchers. According to this study another mode of subsidence can be considered in addition to other states which have been studied by other researchers. New equations and ratios were obtained with appropriate definition and static model analysis and consequently it was found that cracks form depends on the length of the subsidence.