括号部分进行了大幅度的修改，没有主语的句子多数改为被动态，个别处把 this paper 用作主语
沉井基础是以沉井法施工的地下结构物和深基础的一种型式。它由刃脚、井壁、隔墙、井孔、凹槽、射水管组和探测管、封底混凝土、顶盖部分组成。首先在地表制作成一个井筒状的结构物，然后在井壁的围护下，从井内不断挖土，使沉井在自重作用下逐渐下沉，达到预定设计标高后，再进行封底，构筑内部结构。广泛应用于桥梁、烟囱、水塔的基础;
Open caisson foundation is a type of underground structure (sunk by the means of drop shaft) and deepfoundation. It consists of a cutting edge, (shaft wall), partition wall, (well hole), groove, (a group of discharge jets and an exploring tube), (bottom closing concrete), (and top cover). (A shaft shaped structure is firstly made into on the surface of the earth), and then (surrounded and protected by the shaft wall, the open caisson is made sinking little by little under the action of its dead weight) (by the soil’s being continuously dug out of the well) and (after it arrives at the preconcerted design elevation, the bottom can be closed and the inside structure can be built).
首先，本文将工程概况进行介绍，对当地水文地质进行分析。
First of all, (in this paper, an overview of the project is introduced) and the local hydro hydrogeology is analyzed).
其次，本文对当地的环境编写施工方案，介绍其施工工艺；分析沉井施工中的质量通病，如何控制质量通病的发生。
Secondly, (a construction scheme is worked out on the local environment and its construction technology is introduced; also it is necessary to analyze) the quality defects in construction of an open caisson and how to control the occurrence of common quality defects.
再次，本文沉井施工工艺前期准备工作详细说明；对如何下沉、下沉需注意事项进行详细说明。
Thirdly, (the construction technology of caisson preparatory is elaborated; and how to sink and the dos and don’ts of sinking are also paid attention to in detail).
最后，对沉井基础在实际应用中的技术和经验加以体会，对经济效益进行分析。
Finally, (the paper tastes the technology and the experiences of open caisson foundation in the practical application andanalyzes the economic benefit.)