To study the bending behaviour of segmental precast underground diaphragm walls using transverse joints, 2 full size specimens were tested. Both specimens BC and EC were connected using bolts with steel sleeves for position. Specimen BC was consisted of two fully concrete walls while specimen EC had precast holes in the concrete walls for weight reduction. Ultimate strengths, deformations, strains and failure modes were obtained from the test results. A finite element model was developed using ABAQUS and verified against the test results. The verified finite element was used to further analysis the stress state of specimens under loading. It was shown that the bolted transverse joint was able to provide enough stiffness and strength. The precast holes in the concrete walls had minor effect and the design requirement could be satisfied.