油气管道顶管施工中顶力预测模型

Theoretical Model to Predict Jacking Force for Pipe Installations Using Pipe Jacking

顶力计算是顶管施工的重要内容，关系到整个工程的造价和成败。通过对顶力预测进行理论分析，针对混凝土顶管施工建立顶力计算模型，依次计算总顶力的两个组成部分：顶进正面阻力和管周摩擦阻力。采用朗金主动土压力理论计算水平土压力，砂性土采用“水土分算”方法而粘性土采用“水土合算”方法，进而计算顶进正面阻力；结合土柱压力理论和马斯顿压力理论，分别建立相应的管周土压力模型，给出管周总摩擦阻力的计算方法。得到适用条件明确、计算结果可靠的顶力计算公式，该公式的计算结果与工程实例相比较，满足工程要求。

Jacking force calculation is a pivotal content for the pipe jacking construction, which relates to the costs and success of the whole project. Through detailed theoretical analysis on jacking force calculation, this paper establishes a jacking force calculation model for concrete pipe jacking construction and successively calculates the two parts of total jacking force including front resistance and lateral friction resistance for pipe jacking. For the front resistance calculation, horizontal earth pressure is calculated based on Rankine active earth pressure theory and effects of soil and water are calculated separately in sandy soil while they are calculated together in clayey soil. For the circumferential friction resistance calculation, corresponding earth pressure models are established separately and calculation formulas of the lateral fraction resistance are derived in association with the soil column theory and Marston pressure theory. Finally the jacking force calculation formulas are obtained with definite appliance condition and reliable results, which meet the engineering requirement in comparison with result of project cases.