简述电缆通道非开挖施工的安全措施。
["\u3000\uff083\uff09\u901a\u9053\u5f62\u6210\u7684\u540c\u65f6\uff0c\u5e94\u53ca\u65f6\u5bf9\u65bd\u5de5\u7684\u533a\u57df\u91c7\u53d6\u704c\u6d46\u7b49\u63aa\u65bd\uff0c\u9632\u6b62\u8def\u57fa\u6c89\u964d\u3002"]