تحليل و ارزيابي پارامترهاي موثر بر فرونشست زمين

Analysis and evaluate the effective parameters on land subsidence

پديده فرونشست سطح زمين ناشي از عوامل طبيعي و فعاليت‌هاي انساني در نقاط مختلف دنيا و در طي سال‌هاي اخير در كشور ايران به خصوص استان فارس به علت برداشت بي رويه از آب‌هاي زيرزميني، خشكسالي و عوامل ديگر پديدار شده است و سبب آسيب‌هاي جدي به زمين‌هاي كشاورزي، ساختمان‌هاي مسكوني، جاده‌ها و ديگر سازندها و بروز خسارت‌هاي زيست محيطي، اقتصادي و اجتماعي شده است. در اين مقاله با انجام يك پژوهش موردي در دشت مرودشت به بررسي عوامل و پارامترهاي موثر و ارزيابي ميزان تأثير هر كدام بر نشست سطح زمين پرداخته شده است. در اين خصوص نحوه تعيين و تحليل پارامترهاي موثر همچون ميزان افت سطح آب، جنس و ضخامت لايه هاي خاك به خصوص لايه هاي ريزدانه، خصوصيات ژئوتكنيكي خاك مورد بررسي قرار گرفته است و نتايج حاكي از ان است كه جهت انجام محاسبات فرونشست خاك، داده ها و اطلاعات مورد نياز تا حد امكان بايد به صورت دقيق و جامع تهيه شوند و ويژگي‌ها و شرايط متفاوت هر پارامتر در نظر گرفته شود. به عنوان مثال نشست ناشي از افت يكسان آب و يا ضخامت يكسان لايه ريزدانه در اعماق مختلف متفاوت مي‌باشد.

Land subsidence phenomenon caused by natural factors and human activities in different parts of the world. This phenomenon in recent years is appeared in Iran, especially in Fars province due to indiscriminate withdrawal of groundwater, drought and other factors. Land subsidence caused lots of damages to agricultural lands, residential buildings, roads, and other structures and generally created environmental, social and economicAL problems. In this research a case study was performed on the villages of Marvdasht plain in order to study the effective factors and parameters and evaluate the influence of each one on land subsidence. And also was examined how to determine and evaluate the main effective parameters such as water levels falling, material and thickness of soil layers especially finegrained, geotechnical properties of soil layers. Results showed to perform of subsidence calculations the data and requirement information should be prepared accurate and complete as much as possible. It should be noted that the characteristics and different statues of each parameter must be considered. For exle, the amount of settlement is different in Various depth due to same water falling or same thickness of layers.Land subsidence phenomenon caused by natural factors and human activities in different parts of the world. This phenomenon in recent years is appeared in Iran, especially in Fars province due to indiscriminate withdrawal of groundwater, drought and other factors. Land subsidence caused lots of damages to agricultural lands, residential buildings, roads, and other structures and generally created environmental, social and economicAL problems. In this research a case study was performed on the villages of Marvdasht plain in order to study the effective factors and parameters and evaluate the influence of each one on land subsidence. And also was examined how to determine and evaluate the main effective parameters such as water levels falling, material and thickness of soil layers especially finegrained, geotechnical properties of soil layers. Results showed to perform of subsidence calculations the data and requirement information should be prepared accurate and complete as much as possible. It should be noted that the characteristics and different statues of each parameter must be considered. For exle, the amount of settlement is different in Various depth due to same water falling or same thickness of layers.Land subsidence phenomenon caused by natural factors and human activities in different parts of the world. This phenomenon in recent years is appeared in Iran, especially in Fars province due to indiscriminate withdrawal of groundwater, drought and other factors. Land subsidence caused lots of damages to agricultural lands, residential buildings, roads, and other structures and generally created environmental, social and economicAL problems. In this research a case study was performed on the villages of Marvdasht plain in order to study the effective factors and parameters and evaluate the influence of each one on land subsidence. And also was examined how to determine and evaluate the main effective parameters such as water levels falling, material and thickness of soil layers especially finegrained, geotechnical properties of soil layers.this part have a problem