高速公路路基沉降的快速预测方法

A New Formula Model of Fast Predicting Settlement for Expressway Subgrade

高速公路沉降控制的关键是在填筑期末能够及时准确地预测预压路基的沉降,包括欠载、等载或超载预压路段在预压期以及(卸载后)路面施工期和通车后的沉降、速率过程。基于太沙基理论和线弹性假设,提出了一种不需要具备荷载稳定期观测资料,可以及时快速进行沉降预测的方法。研究了多级荷载作用下考虑卸载与回弹的沉降预测模型,探讨了荷载稳定期内速率衰减特性、卸载前后速率变化规律。结合工程实例,讨论了动态反演的实施方法,验证了快速预测方法的可行性、适用性和合理性。

The key of the expressway settlement dynamic control is to predict settlement for preloading subgrade in time and accurately when fill construction is about to be finished, including the settlement process, speeding process of underloading, equal loading or overloading prepressed section during the period of prepressing and road construction, as well as open to traffic. Based on hypothesis of Terzaghi theory and linear elastic, this paper proposes a new settlement prediction method which needs no observation data during the loading stabilization, and may make predictions timely and accurately. This paper also studies settlement prediction model about mult-loading action which takes unloading and spring back factor into consideration, and discusses characteristics of speed attenuation during the loading stabilization and the rule of speed change front-to-back unloading. Through engineering case study, the optimization method of dynamic inverse analysis is put in practice. Furthermore, the feasibility, the applicability and the rationality of the proposed prediction method are verified,