为解决土压平衡盾构压缩空气泡沫系统发泡过程中气液混合参数选择盲目、泡沫浪费严重等问题，结合网式和介质填充式泡沫发生器的特点，设计了复合式泡沫发生器，研制了一种压缩空气泡沫系统，并对其发泡性能进行研究。通过开展泡沫流量、发泡倍率及析液半衰期等试验，确定出影响泡沫发生器发泡性能的主要因素，得出气体流量、液体流量、气体压力等是影响泡沫发生系统发泡的主要因素，确定在进气管道气体压力为0.3 MPa、气体流量约为230 L?min-1、气液比在50条件下时，该压缩空气泡沫系统发泡性能达到最佳。通过泡沫对红黏土进行改良，得出当含水率为26%～29%、泡沫掺入量为10%～45%、气液比为40～75时，适当调整含水率、泡沫掺量、气液比，该红黏土能达到塑性流动状态，并能满足盾构施工要求。

Some problems, i.e. nontargeted gasliquid ratios selection and serious foam waste, exist in compressed air foam system of EPB shield. Hence, a complex foam generator is designed based on nettype and media fillingtype foam generator; a compressed air foam system is developed, and its foaming performance is studied. The main factors, including air flow, liquid flow and air pressure, affecting the performance of foam generator are determined by experiments of the foam flow, foaming ratio and halflife of foam. It is proved that the foaming performance of the compressed air foam system can reach the best when the gas pressure reaches 0.3 MPa, gas flow rate reaches 230 L?min-1 and gas liquid ratio reaches 50. The foam is used in the red clay conditioning test, and the testing results indicate that the red caly can be in plastic and flowing state when water content rate is 26%-29%, foam amount is 10%-45% and gasliquid ratio is 40-75.