One-meter distance on theground can be easily jumped over.
一米远的距离在平地上能轻而易举跳过。
2
The vibrating acceleration on theground is strongest overthe tunnel, and weakens gradually in the lateral directions. It is amplified at a certain distance away from tunnel central line.
地表振动加速度在隧道正上方强度最大,往两侧逐渐减弱,而在离开隧道轴线一定距离部位出现了一加强区。
3
Microwave technology has exited for over half of the century. It transmits the information by ground visual distance in microwave frequency band. It is a kind of wireless transmission technology.