Tunneling

N'ọnọdụ ebe ime oghere dị n'ime ya bụ ájá ájá, nkume sedimentary na siltstone, ịgbanye ihe na-egbutu ịgbà bụ nhọrọ ka mma. Igwupụta ọwara na ndị na-egbutu ịgbà nwere ike ịzenarị adịghị mma na mmetọ nke mgbawa na-ebute.

Ọ bụrụ na ihu siri ike dị n'ime ọwara ahụ, enwere ike iji nkume nkume Yichen bee ya. Buru ụzọ were ihe nkwọ nkume gbutuo ihu ihu n'ime grid, wee jiri ihe mgbawa kụrie ya, nke nwere ike ime ngwa ngwa gwupụta ihe.

N'otu oge ahụ, Yichen na-emepụta bọket na-egweri na bọket nyocha, nke nwere ike gwepịa nkume ahụ e gwupụtara n'ọwara a na-arụ ebe ahụ iji mee ka ọ bụrụ ngwakọta na obere irighiri ihe. Enwere ike iji nchịkọta ndị a mee ihe maka mkpofu na mkpuchi ala maka ijikwa ya ọzọ.