深(shen)基(ji)點錨頭應固定(ding)在鉆空深(shen)部5m處(chu)穩定(ding)巖層內(nei)，淺基(ji)點固定(ding)在鉆孔2-2.5m處(chu)(鉆桿端部位(wei)(wei)置(zhi))。當錨桿錨固范圍內(nei)有離(li)(li)層時(shi)(shi)，頂板(ban)(套管)沿外測筒(tong)(tong)向(xiang)下移動，移動量有由測筒(tong)(tong)標尺(chi)指示。當錨固范圍頂板(ban)離(li)(li)層時(shi)(shi)，外測筒(tong)(tong)與頂板(ban)相對位(wei)(wei)置(zhi)不變，但沿內(nei)測筒(tong)(tong)向(xiang)下滑動，表明頂板(ban)有離(li)(li)層，離(li)(li)層量由內(nei)測筒(tong)(tong)標尺(chi)指示。當錨桿錨固范圍內(nei)、外都(dou)有離(li)(li)層時(shi)(shi)，內(nei)外測筒(tong)(tong)分別有離(li)(li)層顯示，其(qi)顯示值(zhi)之和為總離(li)(li)層值(zhi)。