###### Abstract
Improvement measures were proposed for the problem of excessive deflection at the front end of the guide beam. [PERSON] [17] established finite element modeling of the incremental launching of open-ended steel box girders, and analyzed the stress and strain during the process of incremental launching; it was found that open-ended steel box girders provide a good structural stability during incremental launching construction. [PERSON] [18] pointed out that increasing the contact area between the base of the girder and the piers can effectively increase the localized load-carrying capacity of the girder. [PERSON] [19] proposed a new method for predicting the local stresses of stiffened steel plate girders in incremental launching construction using the XGBoost algorithm, and its prediction results were compared with those predicted by machine learning methods such as Support Vector Machines (SVM), Decision Trees (DT), Random Forests (RF), Adaptive Boost (Adaboost), and Deep Learning (DL), verifying the superiority of this method. All of the above studies are based on the condition that the right and left jacks are in the same working condition. However, when multi-point jacking, the unsynchronized operation of jacks on both sides will cause the tilting of the girder or a lateral offset of the axis, which will affect the normal progress of the incremental launching construction. Therefore, it is important to correct lateral offset during incremental launching construction. [PERSON] [20] believes that every jack location should be monitored for lateral offset and designed a convenient and effective lateral offset test system. [PERSON] [21] carried out mathematical statistics on the monitored lateral offset of the beam, pointed out that the lateral offset during incremental launching construction obeys a normal distribution, and based on this, a lateral offset control threshold was proposed. [PERSON] [22] utilized round thick steel bars instead of steel plates as lateral limiting devices, which significantly reduced friction without affecting the limiting effect. [PERSON] [23] proposed a two-point limiting method, which reduced the number of limiting devices in incremental launching construction; this method is easy to operate and effectively solves the problem of the trajectory being difficult to control during the incremental launching construction of curved girder bridges. In addition to this, the study of stress changes in the girder caused by unsynchronized jacking is also an important part of the control of incremental launching construction. [PERSON] [24] established a finite element model to analyze the changes in local stress when lateral offset or unsynchronized vertical jacking occur during incremental launching construction. The analysis pointed out that both lateral offset and unsynchronized vertical jacking would lead to an increase in local stresses and even the yielding of the steel. [PERSON] [25] analyzed the force on asymmetric slotted PC beams under lateral offset and proposed that the control threshold of lateral offset could be relaxed to 96 mm. [PERSON] [26] carried out numerical simulations of the stress changes caused by lateral offset and found that the lateral offset has a greater impact on the beam stresses in the middle and late stages of a cycle of incremental launching. [PERSON] [27] considered the risk of lateral offset in the risk evaluation index of incremental launching construction, and utilized the fuzzy comprehensive evaluation method to carry out a risk assessment of the dependent project in order to prevent accidents. However, existing studies have focused on the single-parameter study of synchronization in steel box girder incremental launching construction, i.e., with both lateral offset and unsynchronized vertical jacking occurring separately. However, in actual construction, both situations may occur at the same time, which may exacerbate the local stress change [28]. Therefore, it is very important to study the local stress of the beam under the action of two parameters.