Long-term pressurizing of buried glass fiber-reinforced polymer (GFRP) pipe will result in the reduction of stiffness in the pipes. It leads to excessive deflections in long-term design limits. In situ tests were performed for 664 days to measure deflections of buried GFRP pipe with a large diameter of 2. 400 mm. https://journeysgiftes.shop/product-category/nulls-gift-product/