An Investigation to the Function and Meaning of Modern City Form through Stratified Semiotics Approach

City form is one of the main aspects of cognition and analyzing cities. This concept defined as the consequent of relationship between setting of powers (Spatial and non-spatial powers), which knowing them is the first step for designing the Form. One of the main functions of form is its potential for meaning perception and through this the potential of making good city image and creating urban identity. In other word, good city form including spatial and functional factors which makes it, and also insured meaning, making good reading and finally lead to readability, imageability and reinforcing sense of place in city. But the things which happened to cities in modern age, led to the creation of the form which decreased the acceptable function of form to the lowest level. Therefore meaning and cultural discontinuity happened in city form and city faced with dualism in meaning and identity. Therefore this article follows the influence of modern logic on the form of city. Through this survey the influential factors which led to inappropriate encoding and reading of city form defined. For investigating discontinuity in meaning, semiotics approach is used. Through using this method, changing of signs is searched. Therefore semiotics as a theoretical-based method in a frame of an analytical and elite-based technique, help researches to define signs and codes of city form and through this the essence of signs and its changing explored, principles of encoding defined and influential factors which lead to appropriate reading and decoding of form specified. Between different approaches of semiotics using stratified semiotics because of its nature which provides a method for analyzing the text in an interrelationship context, in the semiotic system has chosen. Using this method as a strong framework for analyzing meaning in city as a text (as an open phenomenon), which include different textual layers is applicable and lead to defining the influential contexts on contextualization or decontextualization from the city form. Analyzing the relation between textual layers in the modern city form (as a text) is done on the basis of stratified semiotic's concepts: markedness, hierarchy structures, context and etc. This method help researchers to define: the influential factors which destroyed the relation between layers, cause oppositions, and also lead to the lowest markedness in the modern city form or decontextualize from the text and finally lead to defining the factors which cause meaning discontinuity against continuity of meaning in city form in modern age. The result of this article shows that changing in non-spatial factors of the modern city form as the influential layer in text, decontextualize from the urban form and make problems in perception of meaning and interpretation of users.